You can substitute pinto beans for black beans if you wish. Remember to pick through the bag of dried beans for little pebbles or shriveled beans before dumping them in the slow cooker. The mango-avocado salsa is also a tasty topping for grilled chicken or fish, or serve it with pita or tortilla chips. We love taking a hearty, flavorful protein like these slow-cooker black beans and giving it an exotic spin Your family will love these build-your-own tostadas. We make the bacon optional in this recipe, for those looking for a veggie-only dish. Though, the flavor from the salty bacon slices is hard to beat in any recipe.