Dice all vegetables to the same size dice. About ¼” by ¼ “, because it allows you to get a spoonful of vegetables.
Mince the jalapeno, and make sure you remove the seeds.
Place vegetables in a large bowl, then add the tomato juice, limejuice, and sherry vinegar to the bowl, season with salt and pepper to taste. garnish with cilantro.
Peppers can be tricky to dice. I find it is easier to cut the top and bottom off first then remove the white interior parts and seeds. Then cut it shiny side down on the cutting board. The interior is easier for some reason to cut.