Let's make some tasty tostadas! Spice up your next dinner with this classic Mexican dish. Ingredients: 2 cans black beans 8 tostadas 2 cup shredded cheese Avocado, sliced Hot sauce How to: 1. Preheat oven to 180°. In a small saucepan over medium heat, add beans and 1 cup of water. Bring to a simmer and let simmer until beans are warmed through, about 10 minutes 2. Pound beans with a wooden spoon until most of the beans are smashed.. Add more water as needed to help create a smoother consistency.