Watermelon and Tomato Salad

Whisk vinegar, sugar, salt, and cayenne together in a small bowl.

Quarter and thinly slice onion and toss it in the vinegar mixture. Set aside to let rest until the onion softens and mellows, about 30 minutes.

Remove the rind from the watermelon (save a half cup of flesh and the rind for the next recipe!), cut into 1″ chunks and transfer to a large bowl. Cut tomatoes into 1″ chunks. Combine the tomatoes with the watermelon chunks. Pour in the onion–vinegar mixture along with oil and toss gently with your hands. Add basil and mint and toss gently. Season the watermelon and tomato salad with salt and pepper, to taste.

Serve salad cold or at room temperature.