I think the best way to make something taste good to a kid is to make it look good. It's amazing how thrilled they are when you give them the Alphabet soup when compared to the usual noodle soup.
We changed up our mac and cheese by adding in diced tomatoes and diced onions.. we also occasionally toss in bacon too
my husband and the kid are big fans of adding in the green bean the ones that are sliced.
they have now like a deep fried mac and cheese squares at this local resturant that has Broccoli in it but I haven't been daring enough to attempt deep fried mac and cheese