Ronzoni Macaroni & Cheese - cooking recipe

Ingredients

2 tablespoons butter or 2 tablespoons margarine
1/4 cup finely chopped onion (optional)
2 tablespoons flour
2 cups milk
3/4 teaspoon salt
1/2 teaspoon dry ground mustard (optional)
1/4 teaspoon ground black pepper
2 cups uncooked elbow macaroni
2 cups shredded sharp cheddar cheese
8 ounces sliced American cheese, broken into 2-in . pieces

Preparation

Heat oven to 350. In medium saucepan over medium heat, melt butter; add onion. Cook 2 minutes. Add flour; cook 1 minute, stirring constantly. Stir in milk and seasonings; cook, stirring frequently, until mixture boils and thickens.
Meanwhile, cook pasta according to package directions; drain. Stir cheeses in milk sauce. In 2-Qt. baking dish, stir together pasta and cheese sauce*. Bake for 30 minutes or until hot and bubbly.