Submitted by Debbie Gannaway from Gramma Debbie's Kitchen at Findlay Market
4 cups watermelon, seeded
2 tomatoes, ripe, but not too mushy
3 tsp. sugar
½ tsp. salt
1 red onion, quartered and thinly sliced
½ cup red wine vinegar
¼ cup extra virgin olive oil
Cracked black pepper to taste
Process watermelon and tomatoes in food processor until smooth. Work in batches that fit your processor, so you don't lose a lot of the wonderful juice from the watermelon and tomatoes.
Combine watermelon and tomatoes in a large bowl; sprinkle with sugar and salt, stir to blend well. Let stand 15 minutes.
Stir in onion, vinegar, and oil. Cover and chill at least 2 hours.