As an avid foodie, it makes my culinary heart and soul all warm and fuzzy, to see brussels sprouts finally getting their due respect in this world. They deserve it, gosh darn it! I get it, I used to not respect these green, rolly-polly, kinda smelly lil’ guys. That all changed when I had them properly prepared and cooked. So, if you think you don’t like them… I am here to tell you that you do! You have just been roaming this earth utterly clueless to how amazingly delicious they are!
Simply roasted, or quickly sautéed over high heat, seasoned with a little salt and pepper… Mind blowing delicious. Roasted, paired with sautéed pearl onions, smothered with creamy béchamel sauce, topped with a panko-pine nut-gruyere cheese mixture topping and baked… Ohhhh. My. Gaaaaaawwwwwdddd. The brussels in this gratin are nothing like the memories you hold of your grandmother, mother, or whoever’s sprouts. You know…. Over cooked, mushy, all brown, sad and lifeless. They look, kind of, like they got run over by the Butterball Turkey delivery truck. This brussels sprouts and onion gratin is seriously marvelous. I promise you will love it.
Side Note: I made this and immediately wished I added bacon. You should add bacon for me. Then leave me a comment about how brainless I was for this oversight. If you do want to add some bacon:
1. Cut bacon strips into lardons (or dice)
2. Sauté the bacon until almost crispy and cooked throughout
3. Remove with a slotted spoon
4. Mix the bacon into the gratin when combining the brussels and onions in a baking dish
Brussels Sprouts Gratin with Pearl Onions and Gruyere
- Total Time: 1 hour 10 minutes
- Yield: 4 1x
Description
Forget mushy brussels sprouts and add this cheesy, crispy, béchamel laden vegetable side dish to your holiday spread.
Ingredients
Sauce:
- 1 1/2 tbsp (22 ml) unsalted Butter
- 1 1/2 tbsp (22 ml) All Purpose Flour*
- 1 1/2 cups (360 ml) Half and Half
- 4 sprigs of fresh Thyme
- Pinch of Nutmeg
- Salt and Pepper, to taste
- Heaping 3/4 cup (85 g) Gruyere Cheese- grated (about 3 oz.)
Sprouts & Onions:
- 1 lb (450 g) Brussels Sprouts- ends trimmed, outer layer of leaves removed and cut in 1/2 or 1/4 depending on how large they are (you want them roughly the same size as pearl onions)
- 1 tbsp (15 ml) Butter - melted
- 1/2 Bag of Frozen Pearl Onions (use about 8 oz. / 225 g)
- 2 tsp Extra Virgin Olive Oil
- Salt and Pepper
Topping:
- 2/3 cup (160 ml) Panko Bread Crumbs (can substitute fresh bread crumbs)
- 1/4 cup (60 ml) Pine Nuts - roughly chopped
- 3 Cloves of Roasted Garlic* - minced (can substitute 1 large clove of unroasted garlic, minced)
- 1 tbsp (15 ml) Butter - melted
- Heaping 1/4 cup (30 g) Gruyere Cheese- grated (about 1 oz.)
- 1/2 tsp Sea Salt
- 1/4 tsp Pepper
Instructions
- Preheat the oven to 425 degrees F.
Prepare the Brussels Sprouts:
- Prepare an 8×8 inch baking dish by brushing the insides with some of the melted butter. Add the brussels sprouts, remaining melted butter, 1/2 tsp salt and ⅛ tsp pepper. Toss to coat.
- Spread the brussels sprouts out evenly and roast until almost fork tender, about 15-20 minutes, tossing once halfway through baking time. Remove from oven and set aside.
- Reduce oven temperature to 375 degrees.
Make the Sauce:
- In a medium sized sauce pan, melt butter over medium heat, do not let brown.
- Whisk in the flour to make a roux, and cook, whisking continuously, until blonde in color, about 1 1/2 minutes.
- Slowly whisk in the half and half and increase heat to medium high and bring mixture to a boil. Reduce heat to a gentle simmer over medium low heat. Add sprigs of thyme. Cook until thickened, about 15 minutes, stirring occasionally.
- Season with nutmeg, salt and pepper. Remove thyme sprigs with a slotted spoon and discard. Turn heat off and stir in gruyere cheese. Taste and adjust seasoning. Set aside.
Prepare the Onions:
- Heat olive oil in a sauté pan over medium heat. Add the pearl onions and season with salt and pepper. Sauté until light golden in color, about 7 minutes. Remove from heat and set aside.
Prepare the Toping:
- Combine all ingredients in a small mixing bowl. Set Aside.
To Assemble:
- Add the pearl onions to the baking dish containing the brussels sprouts and stir to mix. Pour the sauce evenly over the vegetables.
- Sprinkle the breadcrumb mixture evenly over top.
- Bake uncovered, 20 minutes, or until sauce is bubbling and top of gratin is golden brown. Allow to rest 5-10 minutes before serving.
- Prep Time: 20 minutes
- Cook Time: 50 minutes
- Category: Side Dish
- Cuisine: French
Nutrition
- Serving Size: 1 serving
- Calories: 360
If You Liked This Recipe, You’ll Love These
- Gruyere and Brussels Sprouts Gratin
- Roasted Pear and Brussels Sprouts
- Honey and Orange Roasted Brussels Sprouts
- Lemon Roasted Brussels Sprouts
Frequently Asked Questions
Why does the recipe roast the brussels sprouts first before assembling the gratin?
The sprouts are roasted at 425°F for 15–20 minutes until “almost fork tender” before the oven drops to 375°F for the final 20-minute gratin bake. This two-stage approach ensures the sprouts cook through without turning mushy — the article explicitly contrasts this with overcooked, “sad and lifeless” sprouts that characterize bad versions of the dish.
How do I make the béchamel sauce for this gratin?
Melt 1½ tbsp butter over medium heat, whisk in 1½ tbsp flour and cook until blonde (about 1½ minutes), then slowly whisk in 1½ cups of half-and-half. Add 4 sprigs of fresh thyme, bring to a boil, then simmer on medium-low for about 15 minutes until thickened. Remove the thyme, then stir in the heaping ¾ cup of grated Gruyere off the heat.
Can I add bacon to this gratin?
Yes — the article includes a step-by-step bacon addition: cut strips into lardons, sauté until almost crispy, remove with a slotted spoon, then mix into the gratin when combining the brussels sprouts and pearl onions in the baking dish before adding the sauce.
Why let the gratin rest 5–10 minutes before serving?
The final instruction specifies a 5–10 minute rest after the 20-minute bake. This allows the bubbling béchamel sauce to settle and thicken slightly, making it easier to portion clean servings rather than having a runny sauce that slides off the plate.
This gratin looks delicious! Brussel sprouts and gruyere sound like a wonderful pair! Will try this one soon :)
Wow!! This looks delicious. I am gonna try it soon. Yummy.
Can’t wait to try this, looks amazing!