The odd combination is just great, and when both the tomato and watermelon are in season, cant be beat for flavor. If you buy watermelon out of season, taste it.... if needed, add a tad more sugar. There's not much you can do to doctor up a bad winter tomato, but I take my chances and its always tasty anyway. Mom Tip: This might be the sweet salad that tricks some youngsters into enjoying tomatoes, if they don't already. The melon and tomato look and taste just about identical.
For 4-6 addictive servings, use 5 cups of COLD seeded watermelon cut in 3/4 inch cubes, and 1.5 lbs. of COLD ripe tomatoes, also cut in 3/4 inch cubes. Its vital to have them the same size so a forkful will deliver both items in one bite. Sprinkle them with a TB of sugar and 1 tsp salt and toss gently to coat. Let it stand 5 minutes.
Slice a small red onion very thinly, then in quarters, and soak in ice water for 15 minutes before draining well. They get sweetly pickled in the marinade too..
Stir together 1/2 c red wine vinegar and 1/4c "x v" olive oil and add the onions. Add to the bowl of fruit, cover and chill at least 2 hours. Gently toss a time or two. Serve icy cold, on field greens, romaine leaves or coarsely chopped romaine sprinkled with fresh black pepper. Serve with a slotted spoon but it's a juicy salad, so you might want to serve with a spoon as well so your guests can enjoy the delicious juice.