Fancy Mac and Cheese

Name: Fancy Mac and Cheese
Ingredients: 1 pound white button or cremini mushrooms, quartered; Olive oil, for drizzling; Kosher salt and ground black pepper; 8 slices thick-cut bacon; 2 yellow onions, peeled, halved and thinly sliced; 5 tablespoons butter, plus more for buttering the pan; 1 1/2 pounds macaroni; 1/4 cup all-purpose flour; 2 cups whole milk; 1/3 cup half-and-half; 2 eggs, beaten; 3/4 cup grated fontina; 3/4 cup grated gruyere; 3/4 cup grated Parmesan; 4 ounces crumbled goat cheese (chevre); 4 ounces crumbled gorgonzola or other blue cheese