Roasted fennel with creamy short grain brown rice, gruyere, mushrooms, onions and white beans is a hearty vegetarian main. Topped with lemony dijon parmesan breadcrumbs, this Roasted Fennel Gratin is full of flavor and so satisfying.
A Hearty Vegetarian Fennel Recipe
Fennel is one of the many vegetables I knew nothing about prior to joining a community supported agriculture (CSA) program years ago. My CSA share was the first to introduce it to me. At first, I mostly ate it raw in salads. Shaved thin, it adds crunch and a subtle anise-like flavor to salads.
I started sautéing it and loved how this simple cooking method changed fennel’s assertive anise notes to a more mellow, earthy favor. Then, I started roasting it.
And let me just say, roasted fennel is game changer.
Roasting Fennel Transforms Its Flavor
Like most vegetables, roasting transforms the flavors through the caramelization of sugars, producing the most sublime sweet, earthy, nutty flavors.
Under high heat and with a bit of olive oil, fennel is transformed, becoming this tender yet meaty, flavorful vegetable.
There are crispy edges too (!!). But put pair roasted fennel with creamy brown rice, mushrooms, white beans, gruyere and a lemony-dijon parmesan bread crumb topping and you’ve got a fennel gratin recipe worth putting in your saved recipes pile!
At a Glance: How to Make Roasted Fennel Gratin
In this recipe roasted fennel takes center stage. Because fennel takes a bit of time to roast, you’ll start on it first. While the fennel is roasting, you’ll multitask, cooking and preparing the other ingredients.
- First, slice the fennel bulbs, and coat the fennel slices in olive oil. Roast the fennel.
- Second, while the fennel is roasting, cook the brown rice (for easy cooking, use my Fluffy Stovetop Brown Rice recipe), saute the onions and mushrooms, grate the gruyere and prepare the Parmesan bread crumbs topping.
- Third, in a large bowl mix the rice, beans, mushrooms, cheese, vegetable stock (or wine), fennel fronds, freshly ground black pepper, and salt. Transfer the mixture to a baking dish.
- Next, shingle the roasted fennel slices on top of the rice mixture.
- Last, top with the Parmesan bread crumbs and bake.
Bake until the gratin is golden or for a darker crust, you can broil it for just a few minutes towards the end of baking.
Love Mushrooms? Check out my collection of 20 Vegetarian Dinner Recipe Ideas With Fresh Mushrooms.
What to Serve with Roasted Fennel Gratin
Sharing this mushroom fennel gratin with a hearty leafy green salad or seasonal veggie is a delicious way to round out your menu. Here are a few side dishes that pair perfectly with this fennel and mushroom gratin:
Love fennel recipes? Then you’ll enjoy my Lemon Garlic Fennel Kale and White Bean Soup.
Traci’s Tips
- Share with a Big Salad: Once this roasted fennel gratin recipe is assembled, it bakes for about 20 minutes. Use this time to whip up a salad like this Vegetarian Kale Caesar Salad or Apple Cranberry Salad with Maple Buttermilk Dressing.
- Make it Vegan: Several makers have written in the comments how they made this recipe vegan. Here’s what they did:
- Dani “added a full bulb of chopped garlic to the mushrooms and left the cheese out.”
- Sharon made a homemade vegan gruyere and parm and subbed those.
- Janet said: “I substituted vegan cheese in place of gruyere and nutritional yeast in place of the parmesan.”
Roasted Fennel, Mushroom and White Bean Brown Rice Gratin
Ingredients
- 3 tablespoons + 2 teaspoons Extra Virgin Olive Oil
- 2 Large Fennel Bulbs with Fronds
- 1 cup (200 grams) Short Grain Brown Rice, about 3 cups cooked
- 12 ounces (344 grams) Crimini Mushrooms , stems removed and sliced
- 1 cup (120 grams) Yellow Onions, diced
- 15 ounces (425 grams) White Beans (Cannellini), drained and rinsed
- 1 1/2 cups (130 grams) Gruyere, grated*** (see note)
- 2 Lemons, one zested and juiced, the other for service
- 1/3 cup (70 grams) Vegetable Broth, low sodium, or white wine / dry vermouth (see note)*
- 1/2 teaspoon Fine Sea Salt
- 1 teaspoon Fresh Ground Pepper
- 1/3 cup (20 grams) Breadcrumbs , use homemade sourdough breadcrumbs if you can (gluten free if needed)
- 1 tablespoon Dijon Mustard
- 2 tablespoons Fresh Grated Parmesan Cheese**, (see note)
Instructions
Get Ready:
- Preheat oven to 425 Fahrenheit (218 Celsius) and place oven rack in the center of the oven. Spray a 9.5 X 12.5 inch (24 x 32 centimeters) gratin or casserole dish with cooking spray. Set aside. Line a sheet pan with parchment paper. Using your hands or a brush, spread one tablespoon of olive oil all over the parchment paper. Set aside.Â
Prepare & Roast the Fennel:
- Cut the fennel fronds off the bulb and chop the herbaceous parts to yield about 1 tablespoon. Set aside. Trim the top of the fennel and just a little off the base. You'll want to keep the fennel in tact at the base as much as possible so that the wedges won't fall apart. Cut fennel in half from top to bottom, then slice in 1/4 inch (25 millimeters) wedges placing the wedges close together but not touching on the sheet pan.
- Brush wedges, throughly with remaining olive oil (you may have some olive oil left over and this will vary depending on the size of the fennel). Roast in oven for 30-35 minutes, checking on them at about 25 minutes. They should caramelize (turn a darker color but not burn). Some will be lighter in color, others will caramelize more-so than others. This is okay. Overall, they need to be tender.
Make the Rice Mixture:
- While the fennel is roasting, cook the brown rice using my Fluffy Stovetop Brown Rice Method or package directions. Add the cooked brown rice to a medium mixing bowl (it's okay if it cools off – but resist to make it a day ahead as the rice tends to dry out in the fridge. The moisture from fresh coked rice adds creamyness to this dish). Â
- In a large sauté pan add 2 teaspoons of olive oil and heat on medium until shimmering. Add the mushrooms, spreading them out in a single layer as best you can and stir only occassionally, about every two minutes for 9-10 minutes. We want them to sear. Add the onion in with the mushrooms and sauté for about 4-7 minutes or until the onions are softened.
- Add the mushroom/onion mixture to the mixing bowl with the rice. Mix in the beans, Gruyere, zest of 1/2 a lemon, 2 tsp of the minced fennel fronds, juice of one lemon, broth or wine, 1/2 teaspoon salt and 1 teaspoon ground black pepper. Taste to adjust seasoning as needed. Spoon into prepared gratin or casserole dish.Â
Make the Parmesan Crust:
- To make the crust, in a small bowl, mix the breadcrumbs, dijon, parmesan, pinch of salt and zest of 1/2 a lemon. Set aside.
Bake:
- Reduce oven temperature to 400 Fahrenheit (204 Celsius). Arrange fennel wedges over the top of the rice mixture, flipping each wedge over so that the darkest caramelized side is up, shingling if needed to fit all the fennel on top. Spread the bread crumbs evenly over the gratin.
- Bake uncovered for 20-25 minutes, or until the cheese is melted and gratin is warmed through. Check the gratin half way through baking to make sure the breadcrumbs aren't getting too dark. If so, lay a piece of foil over the gratin. Â *You can see the difference in the blog post photos and video below the difference in roasting and baking just a bit longer for darker breadcrumbs and fennel. You can also broil the gratin 1-2 minutes for a darker crust.
Serve:
- Sprinkle remaining cut fennel fronds over the top. Serve with lemon wedges and more parmesan if desired.
To Store:
- Store in covered container for up to three days. When reheating, add a few teaspoons of water and cover. Reheat at 350 Fahrenheit (180 Celsius) for about 20 minutes.Â
Video
Notes
Nutrition
Nutrition is provided as a courtesy and is an estimate. If this information is important to you, please have it verified independently.
Made it? Leave a comment below!
The most helpful comment may include recipe rating, feedback, any modifications or helping other commentors.
I searched for a fennel recipe and found your website. I made this recipe last night and it was fantastic! I will definitely be making this again and definitely be checking out more of your recipes. Thanks for a fantastic new resource!
Hi Sally! Thank you for your note and sending a smile! SO happy to hear you enjoyed the recipe… isn’t it amazing the transformation of roasted fennel?
This recipe was amazing. Will definitely make again.
Hi Paula! Thank you for your note and giving the recipe a go. SO happy to hear you enjoyed the recipe!
This recipe was AMAZING. I loved it and we devoured it. Will make again.
WOooo! So happy to hear MM! Thank you for coming back and leaving a note!
Loved it! Substituted rice with bulgur, works well too!
Such great flavors! I made it vegan, and used the following recipe for Vegan Gruyere: https://www.onegreenplanet.org/vegan-recipe/gruyere-cheese/ It was fantastic! I made a Vegan Parmesan that I found online, too. Glad you posted this recipe; thank you for sharing. I had two huge fennel bulbs from my CSA Bag this week, and I feel like this was the best possible way to use them!
Hii Sharon! Thank you for your note, review and vegan gruyere resource! So happy you enjoyed the recipe! Isn’t roasted fennel delicious?!
It says 9.5 inch Casserole dish but the picture shows a much larger oval one…
Says heat the oil until shimmering, does not mention on medium or high or medium high…. So frustrating when these details are not included
Hi Andrew! Thank you for letting me know the directions are unclear. I’ve clarified the dish size (with link to the gratin I use) and heat setting on the recipe card. I’m always responsive to questions on my blog, so if something is unclear, please ask!
So, so delicious. I used white wine. Also, I added a full bulb of chopped garlic sautéed in with the mushrooms and onion. I left out the cheese altogether. New family favorite.
Hi this sounds delicious! I’d like to make it for my guests this weekend. Have you ever Made in two parts? Maybe do some of the steps the night before Roast the fennel sauté the mushrooms and onions cook the rice the night before maybe and finish the rest the day of?
Hi Vanessa! Thank you for your note. I’ve not tried it, but wouldn’t hesitate making the entire recipe up to the crumb topping and place it in the fridge, covered, for maybe one day in advance. When ready to bake, make the crumb topping, top the gratin, then bake it. I hope this helps and you enjoy the recipe!
Wow this was delicious! I made a few tweaks as I’m lactose intolerant.. essentially made it vegan. :) I substituted vegan cheese in place of gruyere and nutritional yeast in place of the parmesan. I also subbed the white wine for the vegetable broth. Good idea! Tasted phenomenal paired with the fennel.
Hi Janet! Thank you for coming back and leaving a note, and sharing your tips! It sounds delicious and I will be giving that white wine a try this fall! SO happy to hear you were able to adapt it to your needs. Thank you again!
I just finished making this (haven’t baked it yet though I’m sure it’s going to be amazing!!!) and I read about the white wine note at the bottom!!! ARRHH!!! what a good idea that would have been. Maybe add Vegetable Stock or White wine in the ingredient list? I’m sure it would be amazing! I will be trying it out next time!
Hi Louise! Thank you for your note.. so sorry you didn’t see the recipe notes. I only list ingredients I’ve tried in a recipe – that’s why I put this idea in the notes – as an option for you to try. I’ve yet to try it, but if I do, I’ll update the recipe. Nevertheless, I hope you enjoy the recipe – it’s fennel season after all. I need to make this again (with a gluten free option!). Thank you again, Louise!
I made this dish as written. Alot of work, my kitchen was a mess but it was very good. Once the fennel was roasted it didn’t taste like fennel anymore. People thought it was onion. The lemon flavour was lovely. It was like a risotto.
Hi Diane! Thank you for your note. I always make such a mess when a gratin is underway! I hope there was someone to help clean up ; ) I agree, roasting fennel completely changes its character… but onions? I’ve not heard that one before! I hope y’all enjoyed it. Thank you for coming back and leaving a note!