My mom's recipe, which is not particularly authentic, is:
dice: 8 large tomatoes, peeled and seeded
2 large onions (not-sweet)
2 green peppers, seeded
2 cucumbers, peeled and seeded
mix with a quart of tomato juice or v-8, and add to taste:
red wine vinegar, olive oil, garlic powder, lemon pepper, hot sauce, S&P.
It is better after a day in the fridge. When I make it, I use a very coarse dice, and fresh garlic in addition to powder. It comes out as much a salad as a soup. I serve it with curried mayo.
-Will