Baked Penne with Farmhouse Cheddar and Leeks

INGREDIENTS

• 2 large eggs
• 1/4 cup (1/2 stick) butter
• 1 tablespoon Dijon mustard
• 1 pound penne pasta
• 3 1/2 cups whole milk
• 1 teaspoon hot pepper sauce
• 1/4 cup all purpose flour
• 1 pound extra-sharp cheddar cheese, coarsely grated (about 4 cups packed)
• 5 cups chopped leeks (white and pale green parts only; about 5 large)