Grown up Mac and Cheese

Name: Grown up Mac and Cheese
Ingredients: 4 ounces thick-sliced bacon; vegetable oil; kosher salt; 2 cups elbow macaroni or 2 cups cavatappi pasta; 1 1⁄2 cups milk; 2 tablespoons unsalted butter; 2 tablespoons all-purpose flour; 4 ounces gruyere cheese, grated; 3 ounces extra-sharp cheddar cheese, grated; 2 ounces blue cheese, such as Roquefort, crumbled; 1⁄4 teaspoon fresh ground black pepper; 1 pinch nutmeg; 2 slices white bread, crusts removed; 2 tablespoons freshly chopped basil leaves