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. This recipe is vegetarian, easily gluten free with notes from makers who made it vegan. [ VIDEO in recipe card below ]
This recipe was first posted January 2017 and has been updated with new photos, text and notes November 2021. The recipe remains unchanged.
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!
How to Make this Vegetarian 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. In summary, here’s how to make this baked fennel gratin (see recipe card for details):
- 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, 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.
What to Serve with Roasted Fennel Gratin
Sharing this mushroom fennel gratin recipe with a hearty leafy green salad is a perfect side to round out your menu. Here are a few salad recipes 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!
A Few Recipe Notes
- 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.
- 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.”
- Freezer Friendly? Yes please! Allow the gratin to cool completely, then transfer to a lidded storage container. Freeze for up to two weeks. Thaw in fridge, gently reheat in the oven.
More Hearty Vegetarian Recipes for Sharing
- Black Eyed Pea Cornbread Pot Pie
- Vegetarian Chili Tater Tot Casserole
- Lentil Cottage Pie
- Mushroom Stuffed Cabbage Rolls
- Butternut Squash and Kale Lasagna
Roasted Fennel, Mushroom and White Bean Brown Rice Gratin Recipe
- 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
- 2 Lemons one zested and juiced, the other for service
- 1/3 cup (70 grams) Vegetable Broth 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)
- Preheat oven to 425 Fahrenheit (218 Celsius) and place oven rack in the center of the oven. Spray a 9 1/2 inch (24 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 according to 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 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.
- 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.
- Sprinkle remaining cut fennel fronds over the top. Serve with lemon wedges and more parmesan if desired.
- 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.