Slice just the tops off of the tomatoes. Using a spoon scrape and scoop out all tomato pulp and seeds. Set aside tomato shells.
In a saucepan over medium heat combine: cooked finely chopped chicken & pesto sauce. Heat for 5 minutes or more until chicken is heated.
Add mayonnaise and stir. Remove from heat.
Fill tomato shells with chicken pesto mixture and sprinkle with grated cheese. Cheese should melt if the chicken is still warm. Can also use a kitchen torch very lightly and quickly over the top to melt the cheese. Serve immediately.
Notes
*all nutritional data are estimates based on the products I used*-Yield: 12 tomatoes, Servings: 6, Serving size: 2 tomatoes. Amounts per 2 tomato snacks: