Combine peppers, tomatoes, onions, garlic, parsley in a bowl with your fingertips. Squeeze the juice of the lemon with the lemon half sitting upright. This will help prevent the seeds from falling into the bowl. The lemon juice will spill down over the sides of the lemon and the seeds will remain with the fruit. Squeeze the juice evenly over the salad. If the lemon is under-ripe, microwave it for 10 seconds before you cut into it. Next, sprinkle a tablespoon of vinegar over the salad -- just eyeball it. Drizzle the extra-virgin olive oil over the salad, add the salt, pepper and cumin. Toss again. Taste to adjust seasonings and serve.