Refried bean and avocado tostadas are a tasty meatless meal. Crispy corn tortillas are topped with refried beans, lettuce, tomato, creamy avocado, and lime scented sour cream. You can add crumbled Mexican cheese, such as cotija, for an extra boost of flavor. Soy chorizo would also be delicious atop these tostadas. Refried bean and avocado tostadas are a stress-free dish for any night of the week.