Cheesy Meatloaf with Green Quinoa

Name: Cheesy Meatloaf with Green Quinoa
Ingredients: 1 cup quinoa; 3 cups baby spinach; 1 cup loosely packed fresh cilantro leaves; 1 large clove garlic; 12 ounces extra-lean ground beef; 8 ounces 99-percent fat free ground turkey; 1/4 cup 2-percent milk; 3 tablespoons whole wheat breadcrumbs; 4 teaspoons Worcestershire sauce; 1 teaspoon chile powder; 1 large egg; Kosher salt and freshly ground black pepper; 4 teaspoons red wine vinegar; 2 small plum tomatoes, cut into 12 slices; 5 tablespoons shredded Cheddar; 12 small slices of watermelon, for serving (8 ounces)