START TO FINISH: 20 minutes MAKES 4 servings • 1 16-ounce can no-salt-added organic black beans, rinsed and drained • 1⁄2 cup canned fat-free refried beans • 1⁄2 teaspoon ground cumin • 1⁄2 teaspoon chili powder • 4 tostada shells • 1 cup shredded lettuce • 3⁄4 cup...

























