I brought this as a first-course soup for a larger meal; it easily served the 6 of us with hefty leftovers. I think the soup would work as a light main course as well, served with a good bread and cheese or hummus.
adapted from http://www.simplyrecipes.com/recipes/watermelon_gazpacho/
1 red onion, cut in half (Half of the first 4 ingredients will be cut in large chunks and then puréed; the other half will be finely chopped and added later.)
1 large green pepper, cut in half
1 English cucumber, cut in half (cross-wise)
1 jalapeno pepper, cut in half
2 cups roughly chopped fresh garden tomatoes (or cherry tomatoes)
7 cups roughly chopped seedless watermelon (or watermelon with seeds removed); this was have of a 5-6 lb. watermelon
1/3 c. chopped cilantro
1/4 c. red wine vinegar (or more to taste)
1 t. kosher salt
1 T. olive oil
sour cream (lite is fine)
diced avocado (I used one for 6 people)
1. Set aside one half of the onion, green pepper, cucumber and jalapeno. Cut the rest in largish pieces, and purée together in a food processor; put into a large bowl.
2. Put the chopped tomatoes in the food processor and purée; add to the mixture in the large bowl.
3. Put the chopped watermelon in the food processor (probably need to do in two batches); purée and add to mixture.
4. Add the 1/4 c. vinegar to the mixture, and then whisk in the salt and olive oil.
5. Take the reserved half of the onion, green pepper, cucumber, and jalapeno, and chop finely. Chop the cilantro. Add all to the mixture in the large bowl. Taste, and add more vinegar and/or salt, if you like.
6. Chill for at least a few hours; chilling overnight is also fine—tastes as good or better the second day.
7. Garnish with sour cream and diced avocado. Also good with a side of toasted artisan bread.