Using a paring knife, slice a circle in the top of each tomato. Scoop the flesh out of tomatoes, leaving about a 1/4 inch-thick tomato “shell.” Drain any excess water out of the flesh you’ve scooped and dice it into 1/4 to 1/2-inch pieces.
Place diced tomato in a mixing bowl. Add all remaining ingredients and mix to combine.
Scoop the mixture into your tomato shells and serve.