In a medium bowl, mash the avocado and chickpeas together with the lemon juice, cumin, garlic powder, and Tabasco (optional) using a fork (or pulse in a food processor to coarsely mash).
Fold in the bell pepper and scallions, then divide among toasted bread. Top with tomato and cucumber slices and a tablespoon of yogurt.
Serve with 8-ounce glass of milk.
430 calories; 12 g fat; 2 g saturated fat; 5 mg cholesterol; 25 g protein; 59 g carbohydrates; 13 g fiber; 460 mg sodium; 440 mg calcium (45% of daily value). Nutrition figures based on using fat free milk, and include an 8-ounce glass of milk.