pound piece of skin-on watermelon, seeds discarded
cup granulated sugar
garlic cloves, peeled and grated
tablespoon whole-grain mustard
teaspoons fresh thyme leaves
teaspoon red-pepper flakes
teaspoon ground black pepper
cup white wine vinegar
cup olive oil
- Make the dressing: Using a coarse grater set over a medium bowl, grate the watermelon flesh then rind, grating the rind all the way to the skin. (You should have about 1 cup grated watermelon.) Discard the firm skin. Add the sugar and 1 teaspoon salt; stir to dissolve the sugar and salt grains. Allow the mixture to sit for at least 10 minutes.
- Add the garlic, mustard, thyme leaves, red-pepper flakes, ground black pepper, vinegar and oil. Whisk together (or transfer to a mason jar, cover and shake vigorously). The dressing makes 2 cups, and will keep, refrigerated, up to 1 week; shake before use.
- Make the salad: Heat the oven to 425 degrees. On a small sheet pan, toss the cubed bread, olive oil, thyme and sea salt together. Spread in a single layer and bake for 8 to 10 minutes, until toasted and golden brown.
- In a large serving bowl, combine the watermelon, tomatoes, cucumber and red onion. Drain any excess liquid before adding the toasted bread cubes and half the basil. Drizzle with 1/4 cup of the dressing and season with salt and pepper. Divide among individual bowls, if you like. Top with crumbled feta, remaining basil leaves and spoon additional dressing over the top.