Tuna Noodle Casserole Melt

Normally I hate tuna noodle casserole---it can turn out very watery & bland. I cooked it up about two nights ago, taking suggestions from a few people as well as adding some things of my own, and really enjoyed it.

approx 2 cups fusili pasta
2 tins tuna
1 can cream of mushroom soup
1 pkg sharp shredded cheddar
1 onion
pepper to taste
milk as needed
3 tomatoes
1 cup (ish) breadcrumbs
olive oil
butter

Cook pasta while cooking onion in olive oil til tender. Mix together cooked pasta, cooked onion, tuna, cream of mushroom soup, large handfull of shredded cheddar, milk, and pepper. Put in slightly buttered casserole dish and top with remaining cheese, breadcrumbs and sliced tomato.