HOT TO MAKE GREEN BEAN CASSEROLE RECIPES

Steps:

• Bring a large pot of salted water to a boil. Add the green beans, and cook until bright green and crisp-tender, about 10 minutes. Drain and shake off any excess moisture; set aside.
• Melt the butter in a medium pot over medium heat. Add the onions, and cook, stirring, until soft, about 8 minutes. Add the mushrooms and a pinch of salt, and continue to cook, stirring, until they are soft and most of their liquid has evaporated, about 10 minutes. Sprinkle the flour over the vegetables, and stir until all the flour has been absorbed, about 1 minute. Add the chicken broth, half-and-half, 3/4 teaspoon salt and several grinds of pepper. Bring to a boil, then reduce to a simmer and cook, stirring, until the sauce thickens and coats the back of a spoon, about 5 minutes. Remove the pot from the heat, add the green beans and stir to coat in the sauce. Transfer the mixture to a 3-quart baking dish.
• Let the casserole cool to room temperature. Wrap well with plastic wrap and foil, label and date, then freeze for up to 2 weeks.
• To serve, preheat the oven to 350 degrees F. Discard the plastic wrap and foil from the frozen casserole. Cover with new foil, and bake until warmed through, about 45 minutes. Uncover, and top with the fried onions. Continue to bake until the casserole is hot and bubbly and the onions have crisped slightly, about 20 minutes more.

Steps:

• Preheat oven to 375 degrees F (190 degrees C). Grease a 9x13 inch casserole dish.
• Heat 2 tablespoons of butter in a large skillet over medium heat. Stir the onions into the pan; cook and stir until very soft and golden brown, about 15 minutes. Stir in sherry vinegar. Transfer to a small bowl, and reserve.
• In the same skillet, melt 2 more tablespoons butter. Whisk in 2 tablespoons flour. Stirring constantly, cook over medium heat until the flour smells like baked pie crust, about 3 minutes. Slowly whisk in milk, about 1/2 cup at a time, then whisk in nutmeg, cayenne pepper, and thyme. Bring to simmer, and cook until thickened, whisking constantly, 3 more minutes. Transfer to a bowl and reserve.
• Melt remaining 2 tablespoons butter in clean skillet; stir in panko until all crumbs are coated; reserve.
• Bring a large saucepan of salted water to a boil over medium heat, and boil beans until bright green and crisp but not raw tasting, 3 to 4 minutes. Drain very well.
• Spoon half of the caramelized onions into the prepared casserole dish; top with green beans. Season with salt and black pepper. Spread reserved white sauce over the green beans; sprinkle with half of the Gruyere cheese. Top with the rest of the onions, and use the back of a spoon to push onions down into sauce and cheese. Top with the buttered panko crumbs, the remaining Gruyere, and Parmesan cheese.
• Bake in the preheated oven until hot throughout and lightly browned, about 30 minutes. Let sit 10 minutes before serving.