Watermelon Gazpacho

Name: Watermelon Gazpacho
Ingredients: 1 medium English cucumber (, peeled, seeded); 2 cups diced tomatoes; 2 cups diced watermelon (, plus more for garnish); 1/2 red bell pepper (, seeds and ribs removed, finely chopped); 1/4 cup olive oil (, plus more for drizzling); 1 tablespoon apple cider vinegar; 1 small jalapeno pepper (, seeds removed, finely minced); 1/2 a shallot (, finely minced); 1 teaspoon coarse salt; 1/4 teaspoon black pepper; sour cream, torn basil, crusty bread (, for serving, optional)