Baked Leek Gratin Recipe

Scoop of leek gratin recipe in a spoon hovering over casserole dish

5 from 2 votes

This baked Leek Gratin Recipe is easy to prepare, full of flavor, and great to make year round. Hard-boiled eggs and sweet, mild leeks are baked in a luscious, creamy cheese sauce. Plus, it's flexible and can be served as a side dish or light entrée.

Prep Time10

Cook Time30

Total Time40

Course: Side Dish

Cuisine: American

Keyword: Leek Gratin, Leek Gratin Recipe

Servings: to 10 servings

Calories: 296kcal

Author: Lee Clayton Roper

Ingredients

8 hard boiled eggs peeled
10 medium medium leeks
6 tablespoons butter divided use
2 tablespoons all-purpose flour
1 ½ cups whole milk, warmed
½ cup shredded white Cheddar cheese around 2 ounces, divided use
¼ cup grated Parmesan cheese
¼ teaspoon cayenne pepper

Instructions

Preheat oven to 450 degrees F.
Cut each egg into 8 pieces. Arrange in a single layer in a 1 1/2 to 2 quart gratin dish (or a 10-inch pie pan). Set aside.
Remove dark green portion of leeks and throw away. Cut off the root end and cut each leek in half lengthwise. Rinse well, making sure to remove all the dirt. Pat dry. Coarsely chop leeks.
In a large skillet, melt 4 tablespoons of the butter over medium heat. Add the leeks and cook until tender, about 5 to 7 minutes. Spoon the cooked leeks over the top of the eggs in the gratin dish – don’t wash the skillet!
In the same skillet, melt the remaining 2 tablespoons of butter over low heat. Whisk the flour into the melted butter until smooth. Cook over low heat, whisking constantly, for 3 minutes. (This removes the raw flour taste from the mixture.)
Slowly pour in warmed milk in a thin, steady stream while whisking constantly to prevent lumps. Continue cooking over low heat, stirring or whisking frequently, until the sauce is smooth, lump-free, and thick enough to coat the back of a spoon.
Whisk in 1/4 cup of the Cheddar cheese, Parmesan cheese, and cayenne pepper. Season to taste with salt and pepper.
Pour sauce evenly over the leeks and eggs.
Sprinkle top with remaining 1/4 cup Cheddar cheese. Bake for 10 minutes or until bubbly and top is golden brown.

Video

Notes

Wash and dry leeks well. Leeks trap a lot of dirt in their layers, so rinse thoroughly and drain well.

Don't wash the skillet. Make the cheese sauce in the same pan you cooked the leeks in so all that buttery leek flavor goes right into the sauce.

Cook the roux the full 3 minutes. This cooks out the raw flour taste. Keep the heat low and whisk constantly so it doesn't brown.

Warm the milk before adding. Warm milk will incorporate faster and result in a smoother sauce.

Make ahead: Gratin can be assembled but not baked up to 24 hours in advance, covered and stored in t:he refrigerator. Bring to room temperature before baking.

Gluten free: Use a gluten-free flour blend.

Note: This recipe was originally published in my cookbook A Well-Seasoned Kitchen®.

Nutrition