In a small saucepan add in the beans and heat for 5 minutes. With a potato masher mash the beans until only bite-size pieces remain and it is spreadable. Add in the red pepper flakes, adobe sauce, cumin, chili powder and lime juice. Stir to combine and set aside.
Spread each tostada shell with 2 tablespoons of heated beans and top corn, bell pepper and onion rings, then the tomatoes and lastly the freshly diced tomatoes.
Recipe by Kitchen Belleicious at https://kitchenbelleicious.com/2011/11/21/src-spicy-black-bean-smoked-corn-and-avocado-tostadas-beyora-giveaway/