Green Bean Casserole

Preheat oven to 375°F.

Heat a large stockpot of water over high-heat until boiling. Trim and cut the green beans. Add the beans to the boiling water and cook for 2-3 minutes. Transfer the beans immediately into a large bowl of ice water, and give them a quick stir. Set aside.

Melt 1/2 tablespoon butter or olive oil in a large sauté pan over medium-high heat. Add the onion and sauté for 2-3 minutes. Transfer the onion to a clean bowl. Add the remaining 1/2 tablespoon butter to the sauté pan, along with the panko, and stir to combine. Cook for 2-3 minutes, stirring constantly, until the panko is lightly golden. Remove from heat, and transfer the panko to the bowl with the onions. Add in the Parmesan, salt, and pepper, and toss the onion mixture until evenly combined. Set aside.

Briefly rinse and dry the sauté pan. Melt the butter over medium-high heat. Add the mushrooms and sauté for 5 minutes. Add the garlic and sauté for 1-2 more minutes. Stir in the flour and sauté for 1 more minute. Add in the vegetable stock, and stir until the flour is evenly dissolved. Add the milk and Parmesan, and stir to combine. Continue cooking the sauce until it reaches a simmer and thickens. Remove from heat, and season with salt and pepper to taste.

Combine the green beans and mushroom alfredo sauce in the stockpot, and stir until evenly combined. Transfer to a 9 x 13-inch baking dish, and spread out in an even layer. Sprinkle evenly with the crispy onion topping mixture.

Bake for about 25 minutes, or until the crispy onion topping is golden and crispy. Serve warm, garnished with extra freshly-cracked black pepper if desired.