When you learn to sharpen and then keep a knife honed it will change your life in the kitchen (A good sharing trick is to go harder than you think in the beginning and softer than you think in the end)
I learned this from watching The "Galloping Gourmet". The tomato should be bigger chunks especially in a salad. It also works for onions but dice them smaller.
Gordon ramsay is one with his knife, basically maxed out the starter pack from start to finish. Since someone else is using a gordon ramsay type of knife, they need to refine the blade and skills from the beginning
My Polish mom showed me how to do this 40 some years ago. Onions are done this way as well, just keep the root attached so the onion doesn’t fall apart when you’re cutting it. I do the same sort of technique with my hot Hungarian peppers, works great!