This recipe is my husband's late aunt's but it was introduced to me by my stepdaughter and it is, by far, the BEST mac n cheese recipe ever! We dig into it and can't stop eating it until the entire pan is gone!
Take a stick of butter and grease an 11x13 glass casserole dish. Boil water and cook rigatoni per the directions on the box and drain.
in a saucepan, melt butter, then add flour and whisk until thick. Add 2 cups of milk and continue to whisk under medium heat until thick and creamy. Don't let the mixture burn! keep whisking, it will get thick.
add noodles to creamy base, add both colby and sharp cheddar cheese and mix well. Pour in additional 2 cups of milk and mix well. Put in a 375 degree oven for 45 minutes.