Put salted water on to boil, and have 12oz pasta ready to pour in at the boiling stage.
Then, on the next burner, create the sauce:
3 Tbl butter
3 Tbl flour
Melt butter in saucepan, whisk in flour and continue whisking for 2-3 minutes over medium heat.
1.5 cups milk
generous sprinkle kosher salt
dash white pepper - optional (my kids won't eat black pepper. it freaks them out.)
Whisk continuously as you pour the milk in to eliminate lumps. Continue to cook on low for 4-5 minutes, whisking occasionally, until thickened. While that's cooking, grate some cheese.
1 cup grated cheddar
When sauce is thickened, pour cheese in and stir to combine.
The pasta should be about 2 minutes away from finishing at this point. Drain when it's done, and pour into your sauce. Serve immediately with a sprinkle of grated cheese on top.
This took me 15 minutes from start to finish, and I didn't feel one bit of guilt at feeding them this, with a salad and apple slices. Somehow, it didn't feel like a give-up dinner, but it only took 5 minutes longer than a box mix. And YUMMY!