Sometimes I will mix in frozen peas at the end to make it pretty and to get our vegetables in. Sometimes I make it with elbow or shells or whatever is on hand. Getting the noodles done at the same time as the sauce can be tricky.
Stovetop Mac n Cheese
From Everyday Food
3 tablespoons unsalted butter
1/4 cup finely chopped onion
1/3 cup all-purpose flour
4 cups whole milk
1/8 teaspoon cayenne pepper
3/4 pound small shell pasta or elbow macaroni
4 cups coarsely grated sharp yellow cheddar (3/4 pound)
1 teaspoon Dijon mustard
1 teaspoon Worcestershire sauce
In a medium saucepan, melt butter over medium; add onion and cook until softened, about 4 minutes. Add flour and 1/2 teaspoon salt; cook, stirring frequently, until mixture is pale golden, has a slightly nutty aroma, and is the texture of cooked oatmeal, about 5 minutes.
Whisking constantly, pour in 2 cups milk; add 2 more cups milk and cayenne and whisk until smooth. Cook mixture, stirring constantly along bottom of pan, until boiling, 6 to 7 minutes. Reduce heat to low. Simmer gently, stirring occasionally, until sauce thickens and does not feel grainy when a small amount is rubbed between two fingers, about 10 minutes.
Meanwhile, in a large pot of boiling salted water, cook pasta until al dente; drain thoroughly and return to pot. Remove sauce from heat and let cool 10 minutes (FYI, I usually skip this step. The one time I did let it cool, it quite didn't coat the noodles like I wanted). Quickly whisk in cheese, mustard, and Worcestershire. Pour cheese sauce over pasta and stir to coat.