Classic Green Beans Au Gratin

Prep time: 25 min
Cook time: 25 min
Servings: 6
Yield: 6 servings

Description

Chef John's green bean au gratin casserole has a creamy, rich cheese sauce that enhances but doesn't cover up the beans so they're still the star.

Ingredients

1 tablespoon unsalted butter, softened
1 1/4 pounds fresh green beans
freshly ground black pepper to taste
kosher salt to taste
2 teaspoons Dijon mustard, or more to taste
1 1/2 cups heavy cream
2 ounces Comté cheese, grated
2 tablespoons freshly grated Parmigiano-Reggiano cheese
2 tablespoons unsalted butter, melted
1/3 cup dry bread crumbs
1 pinch cayenne pepper, or to taste

Directions

1 Preheat the oven to 450 degrees F (230 degrees C). Generously grease a casserole dish with 1 tablespoon butter.
2 Bring a generously salted pot of water to a rolling boil over high heat.
3 Remove stems from beans by trimming with a knife or snapping them off with your fingers. Cut beans in half.
4 Add beans to the boiling water, stir, and cook until just barely tender, 5 to 6 minutes, testing often to make sure you don't overcook them.
5 Remove beans with a strainer and immediately place in a bowl of cold water to stop the cooking process.
6 Once beans have cooled to the touch, use your hands to drain and transfer them into the prepared casserole. It's okay if they're still a bit wet.
7 Season beans with pepper, salt, and Dijon mustard; mix until beans are well coated. Pour in cream, scatter Comté cheese over top, and sprinkle with Parmigiano-Reggiano.
8 Combine melted butter and bread crumbs in a small bowl. Stir until well combined and mixture resembles wet sand. Spoon and sprinkle bread crumbs over the casserole, then dust with cayenne.
9 Bake in the center of the preheated oven until browned and bubbly, 15 to 20 minutes.
10 Let cool for 10 minutes before serving.