Yield: 4 servings
Flake tuna and combine with beans, corn, cheese, dressing and onions in a medium bowl. Cover and chill 1 hour.
Just before serving, core tomatoes and scoop out center to within 1/4 inch of edge, forming a bowl; discard flesh and seeds. Cut each tomato into wedges, leaving bottom of tomato intact. Gently open each tomato to support the salad. Arrange tuna mixture on top of the tomatoes.
Please note that some ingredients and brands may not be available in every store.