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.
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).
- 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.
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. *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.
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.
This ended up being one of the best things I’ve ever cooked. I followed the recipe exactly. So dang delicious!
Best news ever, Amanda! Thank you for your note and coming back to let us know. Day made!
I made this last night – I’m trying a lot of your recipes for the upcoming holiday weekend. this was a big hit and pretty easy – I did cut the fennel wrong though – even though I read wedges, I cut slices, it was fine. My question, is it supposed to hold together after baking?
Hi Maggie! Yay! So excited! The gratin shouldn’t hold together (I’m thinking like a stuffing), although there will be some sticking together.
Traci, your recipes are so creative and beautiful. This one deserves 5 stars just for the gorgeous picture which makes my mouth water. Looks like I’ll be buying some fennel and making this recipe. I’ve made so many of your recipes and often forget to review.
: (
I shall try to be more active in the reviewing part. Thanks for all your hard work making great new recipes for anyone and everyone. Cheers.
Thank you, Shannon, for sending a smile and trying the recipes! Your note made my day ☺️
I should add that I used Trader Joe’s frozen brown rice medley right from the freezer for the brown rice portion.
Love it!
I made this and it was fantastic. Just a few minor tweaks, such as using spray olive oil to roast the fennel, and dry-seared the mushrooms and onions (since it works fine without additional oil), and Trader Joe’s grated Swiss and Gruyere. I also used a whole wheat, English muffin from Trader Joe’s pulsed up for the crumbs, and added a small, finely grated clove of garlic to the crumbs with the other ingredients. Superb!
Hi Joyce! Hooray! Thank you for your note, tips (Swiss + gruyere – wow) and giving the recipe a go! SO happy to hear you’re enjoying the recipe.
I made this last night and it was really fantastic. There are so many casserole recipes out there that are delicious, but largely the same. The roasted fennel and the lemon put this one over the top! I added a little bit of salt with the onions, and also on the fennel before roasting and it was perfect.
Hii Jodie! I’m thrilled to read your note and appreciate your star rating! Thank you for your tip about the salt… so happy you enjoyed this gratin!!
I didn’t measure anything as we were cooking for two and using it to clean the fridge, but even my carnivorous husband was quite pleased!
Thank you for your note, star rating and giving the recipe a go! SO glad it worked out and your carnivorous husband enjoyed it too 😃
Fennel is a favorite and now so is this recipe. I added extra topping for more crunch and used a mix of mushrooms that I had in the fridge – left over from the lentil cottage pie recipe – also delicious! The lemon comes through nicely. More fennel recipes please Traci!!
Hi Carolyn! You’re a fan of fennel too! Hooray! I feel like it doesn’t get the love it deserves. Extra topping for more crunch sounds perfect and I’m thrilled to hear you enjoyed the cottage pie too. I’ll see what I can do in the fennel department, Carolyn! Thank you for your note :D
Thank you for sharing this recipe. I was using fresh fennel for the very first time and the family absolutely adored it. I just added a few drops of Tabasco for a little heat. The lemon give a lovely freshness. Will definitely make it again.
Hi Rema! So happy to hear you and your family enjoyed the recipe! I love how roasting the fennel mellows it’s louder raw notes. Thank you for your note!
Delicious! I used wine instead of broth. You don’t mention the beans in the directions so I forgot to put them in.
Hi Leah! So happy to hear you enjoyed the recipe. Thank you for your note. The beans are added in step 4. “Add the mushroom/onion mixture to the mixing bowl. Mix in the beans, Gruyere, zest of 1/2 a lemon…” I hope this helps!