Bell Pepper Gratin with Fennel and Portobello Mushrooms

I used some Allrecipes inspiration to create this dish, as well as some of the process I used to make my zucchini gratin. It's a perfect Christmas side dish or an everyday entrée! You can use any color bell pepper or combination you like.

Prep Time:
15 mins
Cook Time:
35 mins
Total Time:
50 mins
6 servings


  • 1 red bell pepper, halved and seeded

  • 1 green bell pepper, halved and seeded

  • 1 yellow bell pepper, halved and seeded

  • 1 orange bell pepper, halved and seeded

  • 4 tablespoons butter

  • 2 portobello mushrooms, diced

  • 2 bulbs fennel, chopped, fronds reserved

  • 1 clove garlic, minced (Optional)

  • 1 ½ tablespoons all-purpose flour

  • ¾ cup heavy cream

  • 1 cup finely grated Gruyere cheese

  • 1 pinch salt and freshly ground black pepper to taste

  • 2 pinches ground nutmeg (Optional)

  • 2 tablespoons chicken broth, or more to taste

  • ¼ cup freshly grated Parmesan cheese


  1. Preheat the oven to 375 degrees F (190 degrees C). Line a baking dish with aluminum foil.

  2. Place halved bell peppers cut-side down on the prepared baking sheet and bake in the preheated oven for 15 minutes.

  3. Meanwhile, melt butter in a skillet over medium heat and cook portobello mushrooms and fennel until fennel is golden, 10 to 15 minutes. Add garlic during the last minute of cooking.

  4. Remove roasted bell peppers from oven and increase oven temperature to 400 degrees F (200 degrees C).

  5. Chop bell peppers into pieces and add to the mushroom mixture in the skillet. Mix flour into the skillet. Pour in cream in a steady stream and stir until thickened, 3 to 5 minutes. Mix in 1/2 of the Gruyere cheese. Remove from heat and stir until cheese has melted.

  6. Add 1/2 of the vegetable saute mixture to a baking dish. Sprinkle with a couple of tablespoons Gruyere cheese and season with salt, pepper, and nutmeg. Add the remainder of the vegetable mixture and add chicken broth to prevent the gratin from creating air bubbles. Top with remaining Gruyere cheese, Parmesan cheese, nutmeg, salt, and pepper. Garnish with fennel fronds.

  7. Bake in the preheated oven until gratin is bubbly and golden brown, 18 to 20 minutes.

Editorial Note:

For a vegetarian version replace the chicken stock with vegetable stock.

Nutrition Facts (per serving)

322 Calories
27g Fat
11g Carbs
10g Protein
Nutrition Facts
Servings Per Recipe 6
Calories 322
% Daily Value *
Total Fat 27g 35%
Saturated Fat 17g 83%
Cholesterol 88mg 29%
Sodium 279mg 12%
Total Carbohydrate 11g 4%
Dietary Fiber 3g 12%
Total Sugars 2g
Protein 10g
Vitamin C 51mg 255%
Calcium 325mg 25%
Iron 1mg 6%
Potassium 497mg 11%

* Percent Daily Values are based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie needs.

** Nutrient information is not available for all ingredients. Amount is based on available nutrient data.

(-) Information is not currently available for this nutrient. If you are following a medically restrictive diet, please consult your doctor or registered dietitian before preparing this recipe for personal consumption.