Spicy Tofu Stir Fry

Name: Spicy Tofu Stir Fry
Ingredients: 1 pound firm or extra-firm tofu, cut into 3/4 inch cubes ( (see Kitchen Notes)); 3 tablespoons cornstarch; 2 tablespoons olive oil, divided; 1 garlic clove, minced; 1/2 cup white onion or shallot, chopped; 1 cup green bell pepper, cut into small chunks; 1/2 teaspoon freshly ground black pepper; 1 cup cucumber, cut into 1/2 inch coins ( (see Kitchen Notes)); 1 or 2 green onions, cut into coins, for garnish ( (optional)); 2 teaspoons cornstarch; 1/2 cup soy sauce; 2 tablespoons hoisin sauce; 1 teaspoon minced ginger; 1 teaspoon hot soybeans or chili paste ((see Kitchen Notes)); 1/2 cup water ((may need more))