Cauliflower Gratin

Cheesy cauliflower gratin with nutty Gruyere cheese, sautéed leeks, and butter toasted breadcrumb topping!

Cauliflower Gratin
Elise Bauer

Cauliflower gratin. How to transform the simplest of vegetables into a creamy cheesy rock star side dish? Cook it into a gratin.

I love cauliflower. I love it raw as a crunchy healthy snack. I love it roasted with crispy browned edges. I love it in a cheddary soup. Or puréed into fake mashed potatoes. Cauliflower has to be one of the world's most adaptable and dress-up-able vegetables.

No where is cauliflower's haute capabilities more clear than in a gratin. Honestly it's hard to go wrong given that we are smothering lightly steamed cauliflower in a cheesy Gruyere and leek béchamel, and baking it topped with butter toasted fresh breadcrumbs.

Cauliflower Gratin
Elise Bauer

It's as if the vegetable wanted to remind us of what she is capable of.

A worthy side to glazed ham, roast beef, brisket, or roast chicken.

Cauliflower Gratin

Prep Time 15 mins
Cook Time 45 mins
Total Time 60 mins
Servings 6 servings


  • 1 head cauliflower, cored, broken into bite-sized florets (see How to Cut and Core Cauliflower)
  • 2 medium-small leeks, cleaned, halved lengthwise, sliced into 1/4-in thick slices, white and light green parts only, about 2 cups
  • 2 Tbsp butter
  • 2 Tbsp all purpose flour
  • 1 1/3 cups milk
  • 4 ounces Gruyere cheese, grated
  • 1 teaspoon minced fresh thyme or 1/2 teaspoon dried thyme
  • 1/8 teaspoon grated nutmeg
  • 1 teaspoon salt
  • Pepper
  • Topping:
  • 1 1/2 cups fresh breadcrumbs (3 slices of sandwich bread or rustic bread, pulsed in a food processor)
  • 1 Tbsp butter
  • 1/4 teaspoon salt
  • Pepper


  1. Cook the leeks:

    Melt butter on medium heat in a medium sized saucepan. Add the sliced leeks and gently cook until completely softened, about 8 to 10 minutes.

    Elise Bauer
  2. Lightly steam the cauliflower:

    While the leeks are cooking, place cauliflower florets in a steamer basket in a saucepan over an inch of water. Bring water to a boil, cover, and steam the cauliflower for 3 to 4 minutes.

    Elise Bauer

    The steaming should just take the rawness out of the cauliflower, but not cook it so much that it is tender. You want the cauliflower at this stage to be al dente. Remove strainer and cauliflower from hot pan and set aside.

  3. Make roux with butter, leeks, flour, add milk:

    Add 2 Tbsp of flour to the leeks and butter. Stir and let cook for a minute or two. Slowly add the milk, stirring as you add it to break up any lumps. Bring to a low simmer and continue to stir as the sauce thickens.

    Elise Bauer
    Elise Bauer
  4. Stir in cheese, thyme, nutmeg, salt:

    Once the sauce is thick enough to coat the back of a spoon, stir in 3 ounces of the shredded cheese (reserving the rest of the cheese for the topping), the thyme, nutmeg, and salt.

    Elise Bauer
  5. Preheat oven to 400°F
  6. Pour sauce over cauliflower in gratin dish:

    Spread a teaspoon of butter over the insides of a 2-quart gratin dish. Place the lightly steamed cauliflower florets in an even layer in the dish. Pour the leek and cheese sauce over the cauliflower. Top with remaining cheese.

    Elise Bauer
  7. Bake at 400°F for 25 minutes
  8. Toast breadcrumbs:

    While the gratin is baking, melt 1 Tbsp of butter in a small sauté pan on medium high heat. Add the fresh breadcrumbs and toast in the melted butter for 4 to 5 minutes, until lightly browned. Sprinkle with 1/4 teaspoon of salt, and a sprinkling of pepper. Remove from heat.

  9. Top gratin with toasted breadcrumbs and bake:

    After the gratin has baked for 25 minutes, remove it from the oven. Sprinkle toasted breadcrumbs over the top and return to the oven. Bake for 5 more minutes.

    Elise Bauer


How to Cut and Core Cauliflower

Cauliflower Gratin
Elise Bauer