Classic Macaroni and Cheese

I made this recipe (tripled) for Elise's birthday party and everyone said it was just like Boston Market!
http://www.recipezaar.com/236891

1 lb macaroni
6 tablespoons butter
1/2 cup diced onions
1/4 cup all-purpose flour
1 teaspoon salt (to taste)
pepper
4 cups milk (we use skim)
2 lbs Velveeta cheese, cubed

1. Preheat oven to 350 degrees.

2. Cook macaroni according to package directions. Drain and set aside.

3. Meanwhile, in large sauce pan melt butter. Cook onion in butter till tender but not brown.

4. Stir in flour, salt, and pepper. Cook one minute.

5. Pour in milk. Cook and stir until thickened and bubbly, be sure to scrape bottom as it cooks. Cook and stir 1-2 minutes more.

6. Stir in cheese. Heat and stir until cheese is melted.

7. Stir in cooked macaroni. Pour into large 3 quart casserole dish. Bake at 350 degrees for 45 minutes.

Servings: 10