Add the onion and cook for 5 minutes, stirring occasionally until onion is soft and translucent. For a simple change of texture and appearance, replace the elbow macaroni with mini penne or small or medium shell pasta. Melt the butter in a large skillet over medium-low heat.Make it a little spicier with some finely chopped jalapeno pepper. Use part or all pepper jack cheese in place of the cheddar.

For some Tex-Mex color and flavor, add about 1/4 cup of sliced ripe olives, a small can of chopped mild green chile peppers, and 1/2 cup of diced red bell pepper.

For a main dish option, add about 1 to 1 1/2 cups of cooked diced ham to the macaroni and cheese mixture. Or brown about 1/2 pound of ground beef or pork sausage along with 1/2 cup of chopped onion.

To make a mac-n-cheese with bacon, stir about 1/4 cup of diced cooked bacon into the sauce along with the cheese and macaroni.

Sprinkle the breadcrumbs over the casserole before it goes into the oven.

Add a breadcrumb topping: Omit the extra 1/2 cup of cheese in this recipe and toss one cup of fine soft breadcrumbs with two tablespoons of melted butter.

Rue for macaroni and cheese