My son does these all the time and he's getting really good at making them. It's not really alfredo sauce, but it's close. It only uses one pot, a colander, and a spoon, so it's easy on the dishes. And it tastes great.
One-Pot Alfredo Noodles
1 lb uncooked macaroni or noodles, whatever shape you want (bowties, elbows, shells, etc.)
1/4 c. butter
2 T. flour
2 c. milk
1 t. salt
1/2 t. ground black pepper
1/2 t. dried oregano
1/2 c. shredded cheese (or more if you want it cheesier), this can be parmesan, mozzarella, cheddar, or any cheese you want to use
1/2 c. chopped salami (optional)
1 c. steamed broccoli or frozen chopped veggies (also optional)
In a large saucepan, bring 2-3 quarts of water to a boil. Cook the noodles according to the package directions. Drain and set aside.
In the same pot, melt the butter. Stir in the flour. Cook and stir for a minute or so until it's smooth, creamy, and bubbly. Stir in the milk with a whisk. Make sure you whisk it long enough to smooth out any lumps. Add the salt, pepper, and oregano. Cook and stir until it comes to a boil and thickens. Remove from the heat. Add the cheese and stir until the cheese melts.
Add the noodles, salami, and veggies. Stir gently to coat. Serve with extra cheese to sprinkle on top. Serves 2-8, depending on who is eating it.