Macaroni and cheese is generally not a problem for the soy allergic, because there are not a lot of places in it to sneak soy. I suppose somebody could use margarine instead of butter, and those pesky breadcrumbs on top could be made out of supermarket bread, but here we are talking about somebody else's homemade mac & cheese. If you make the kind in the box--and I admit I have--it is pretty straightforward, and non-allergenic if you use butter.
In any case, the following recipe is just as fast as the boxed kind, and tastes better:
Fast-as-the-Boxed-Kind Macaroni and Cheese
12 oz shell or elbow macaroni (3/4 of a 16-oz box)
1/4 cup all-purpose flour
1 tsp minced dried onion (optional)
1/2 tsp Old Bay seasoning or celery salt (optional)
1 tsp grainy mustard (optional)
1/4 tsp Worcestershire sauce (optional)
2 cups milk
8 oz shredded cheddar cheese (can use the preshredded kind. it comes in 8-oz bags.)
1.) Cook the macaroni as the package directs, stopping at the least amount of time specified (for example, if it says 9-11 minutes, stop at 9 minutes). Drain. Put the macaroni back into the same pot, off the heat.
2.) Sprinkle the macaroni with the flour, onion flakes, and Old Bay Seasoning or celery salt. Add the mustard and Worcestershire sauce. Stir to coat the macaroni with the flour.
3.) Put the heat back on to medium, and slowly add the milk, stirring constantly. Cook until the mixture bubbles and turns thick.
4.) Add the cheese and stir until it melts.