Bacon Mac and Cheese

Name: Bacon Mac and Cheese
Ingredients: 12 ounces sliced bacon (9 to 12 slices, not thick-cut); 1 pound dried elbow macaroni; 8 ounces sharp cheddar cheese, shredded (about 2 cups); 8 ounces Monterey Jack cheese, shredded (about 2 cups); 1/3 cup all-purpose flour; 1 1/2 teaspoons ground mustard powder; 5 cups whole or 2% milk; 3/4 teaspoon kosher salt, plus more for the pasta water