Classic Green Beans Au Gratin

Instructions

• Preheat the oven to 450 degrees F (230 degrees C). Generously grease a casserole dish with 1 tablespoon butter.
• Bring a generously salted pot of water to a rolling boil over high heat.
• Remove stems from beans by trimming with a knife or snapping them off with your fingers. Cut beans in half.
• 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.
• Remove beans with a strainer and immediately place in a bowl of cold water to stop the cooking process.
• 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.
• 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.
• 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.
• Bake in the center of the preheated oven until browned and bubbly, 15 to 20 minutes.
• Let cool for 10 minutes before serving.