Insert the tip of the knife around the edges of the core and cut at an angle. Once you go all the way around, the core should come right out.
Slice the tomato into ¼-inch slices. You can do this horizontally and veritcally.
With the tip of the knife, push away the seeds and accompanying gel, leaving just the meat of the tomato behind.
Cut the slices into ¼-inch strips.
Cut the strips into ¼-inch dice.
Notes
Choose tomatoes that are firm, heavy-for-their-size, and deeply colored without any noticeable bruises, cuts, or blemishes. Store them at room temperature to preserve their flavor.Ripe tomatoes can be refrigerated to stop them from over ripening, but you may notice a loss of flavor. Use chopped tomatoes right away in the recipe or store them in an airtight container in the refrigerator for up to 2 days.