This is what I like to make when I have had a really busy day and I come inside from entertaining kids right at dinnertime and haven't even given dinner a single thought. I can throw this together in 10 minutes or less and it really is so good. I always use canned chicken (I love the Kirkland brand canned chicken from Costco) but you can use tuna as well.
tuna or chicken (canned)
Toast bread and place on a cookie sheet. Mix your chicken or tuna with mayo;, celery and green onions. Put chicken mixture on each piece of toast, top with crushed pineapple and cheese. Put under broiler until cheese is melted and bubbly. Salt and pepper to taste.