I've made mac & cheese using chicken soup - 1 pack pasta (cooked), mix in 1 tin chicken (or chicken & corn) soup, add some corn (creamed corn works well), about 250g grated cheese. Pour in to baking dish, top with more grated cheese. Put in oven 180 - 200 C for about 30min. Yummy!

(I usually make mac & cheese with tomato soup but this is a nice alternative)