Baked Cauliflower Gratin
A creamy, cheesy cauliflower gratin with a golden, crunchy breadcrumb topping. High in fiber and plant-based protein, this low-carb side dish is easy to prepare and makes a perfect make-ahead option for holidays or weeknight dinners.
Equipment
- 1-Medium pot
- 1 medium saucepan
- 1 medium sauté pan
- 1 medium casserole dish (buttered, deep enough for 7 servings)
- Whisk
- Spoon or spatula
Ingredients
For the Cauliflower Filling:
- 1 large head cauliflower cut into florets (about 2 ½ lbs or 6–7 cups)
- 3 tbsp butter plus extra for greasing
- ¼ cup all-purpose flour
- 1 ½ cups reserved cauliflower cooking water
- ¼ cup heavy cream
- 2 tsp kosher salt plus more to taste
- Freshly ground black pepper to taste
- ¼ tsp ground nutmeg
- 6 oz Gruyere cheese grated (about 3 cups), divided
For the Topping:
- 3 tbsp butter
- 1 clove garlic finely minced
- 1 ¼ cups panko breadcrumbs
- 1 tsp fresh thyme leaves
- Salt and pepper to taste
Instructions
- Prepare the Cauliflower Florets: Begin by trimming your large cauliflower head and cutting it into evenly sized florets, roughly 1 to 2 inches each. Even-sized pieces ensure they cook uniformly. Rinse the florets under cold water to remove any dirt or debris. Set aside while you prepare your cooking water.
- Blanch the Cauliflower: Place the cauliflower florets in a medium pot and add just enough room-temperature water to barely cover the bottom of the pot. The goal is to cook the cauliflower lightly while preserving its concentrated flavor, so avoid overfilling with water. Bring the water to a gentle simmer over medium heat, cover the pot, and cook the florets until they are tender but still slightly firm, about 2–3 minutes. This ensures the cauliflower remains al dente and holds its shape in the gratin.
- Drain and Reserve Cooking Liquid: Carefully drain the cauliflower in a colander and reserve 1 ½ cups of the cooking liquid. This flavorful water will be used to make the cheese sauce, adding depth to the dish without extra fat or cream. Pat the cauliflower dry with paper towels to remove any excess moisture, which prevents a watery gratin.
- Preheat and Prepare the Casserole Dish: Preheat your oven to 400°F (200°C). Generously butter the inside of a medium-sized casserole dish to prevent sticking and add richness. Make sure to coat the sides and corners evenly so the gratin lifts easily after baking.
- Make the Cheese Sauce Base: In a medium saucepan over medium heat, melt 3 tablespoons of butter. Once melted, sprinkle in ¼ cup of all-purpose flour and whisk continuously for 1–2 minutes. This step cooks the raw flour taste out and forms a smooth roux. Continue whisking until the mixture becomes slightly golden and aromatic.
- Incorporate the Reserved Cooking Water: Gradually pour 1 ½ cups of the warm reserved cauliflower water into the roux, whisking constantly to avoid lumps. Bring the mixture to a gentle boil, then reduce heat and simmer for 2–3 minutes. The sauce should thicken slightly, creating a smooth, velvety base for the cheese.
- Add Cream, Seasonings, and Gruyere Cheese: Stir in ¼ cup of heavy cream, 2 teaspoons of kosher salt, a pinch of freshly ground black pepper, and ¼ teaspoon of ground nutmeg. Mix thoroughly to combine. Then, add one-third of the grated Gruyere cheese (about 1 cup), stirring until melted and fully incorporated. This creates a rich, flavorful cheese sauce that will cling perfectly to the cauliflower.
- Combine Cauliflower with Cheese Sauce: Gently fold the drained cauliflower florets into the cheese sauce, making sure each piece is coated evenly. Taste the mixture and adjust seasoning with additional salt or pepper if needed. This step ensures every bite is creamy, savory, and perfectly seasoned.
- Transfer to Casserole Dish: Spoon the cauliflower and cheese mixture into the prepared casserole dish, using a spatula to scrape every bit of sauce from the saucepan. Spread it evenly so the gratin cooks uniformly. Sprinkle the remaining Gruyere cheese over the top for a golden, cheesy layer.
- Prepare the Breadcrumb Topping: In a medium sauté pan, melt 3 tablespoons of butter over medium heat. Add 1 finely minced garlic clove and sauté until fragrant, about 30 seconds. Stir in 1 ¼ cups panko breadcrumbs, 1 teaspoon fresh thyme leaves, and a pinch of salt and pepper. Continue to cook, stirring constantly, until the breadcrumbs are evenly toasted and golden brown, approximately 5 minutes. This topping will add a crunchy, flavorful contrast to the creamy gratin.
- Top the Cauliflower Gratin: Evenly spread the toasted breadcrumb mixture over the cauliflower and cheese in the casserole dish. Make sure the breadcrumbs cover the surface completely to create a uniform, golden crust.
- Bake Until Bubbling and Golden: Place the casserole in the preheated oven and bake for 20 minutes, or until the topping is a rich golden-brown and the gratin is bubbling around the edges. The aroma should be deeply cheesy with hints of roasted cauliflower and thyme. Keep an eye on the top to ensure it doesn’t burn; if necessary, cover loosely with foil in the last few minutes.
- Rest Before Serving: Remove the gratin from the oven and let it rest for 10 minutes. This allows the cheese sauce to set slightly, making it easier to serve and enhancing the flavors. Garnish with extra thyme if desired.
- Serve and Enjoy: Scoop out portions of the gratin onto plates or a serving platter. This dish pairs beautifully with roasted meats, grilled fish, or as a hearty vegetarian main. The creamy interior, cheesy richness, and crisp topping make it a comforting, nutritious, and satisfying addition to any meal.
Notes
- Choose fresh cauliflower with tight, firm florets for the best texture and flavor. If using frozen, ensure it is fully thawed and drained before cooking to prevent excess water.
- Blanching the cauliflower briefly keeps it tender-crisp and ensures the cheese sauce clings perfectly. Avoid overcooking during this step, as it can make the gratin mushy.
- Reserve the cauliflower cooking water; it adds a natural, mild flavor to the cheese sauce while reducing the need for additional cream.
- When toasting the panko topping, watch carefully to achieve a golden brown without burning. Stirring frequently ensures even color and flavor.
- This gratin can be made a day in advance. Simply refrigerate after assembling, then bake just before serving for convenience and enhanced flavor.
