GREEN BEAN CASSEROLE WITH WALNUT BACON CRUMBLE

Steps:

• Preheat the oven to 475°F.
• Make the topping:
• In a large cast-iron skillet over medium heat, cook the bacon until it is lightly crisp (it will cook a little more in the oven, so no need to get it extra crispy). With a slotted spoon, transfer the bacon to a paper-towel-lined plate to drain. Add the onion to the bacon drippings (there should be about 1 tablespoon in the skillet; if there's way more than that, pour out some and save it for future use). Cook the onion until it is soft and tender, about 8 minutes. Transfer it to a bowl.
• Add the walnuts to the same pan and cook, shaking the pan often, until they are lightly golden, about 5 minutes. Add the walnuts to the bowl with the onion and crumble in the bacon. Add the parsley and toss the whole mixture well. Set aside.
• Wipe out the skillet (you'll be using it again).
• Make the beans:
• Bring a large pot of heavily salted water to a boil. Add the beans and blanch them for 5 minutes. While they cook, prepare a large bowl of ice water. Drain the beans in a colander and immediately plunge them into the ice water to stop the cooking. Drain them again and set them aside.
• Make the sauce:
• Melt the butter in the cast-iron skillet set over medium-high heat. Add the mushrooms and a hefty pinch of salt and pepper and cook, stirring occasionally, until the mushrooms begin to give up some of their liquid, 4 to 5 minutes. Add the garlic and nutmeg and continue to cook for another 1 to 2 minutes. Sprinkle the flour over the mixture and stir to combine. Cook for 1 minute. Add the broth and simmer for 1 minute. Decrease the heat to medium-low and add the cream. Cook until the mixture thickens, stirring occasionally, 6 to 8 minutes.
• Remove the pan from the heat and add the green beans. Sprinkle them evenly with the bacon and onion mixture and bake until bubbly, approximately 15 minutes.
• Serve immediately.