Add black beans and salsa to a medium saucepan and gently heat to warm beans. Stir on occasion to prevent scorching.
While black beans are heating, prepare guacamole by adding avocados, onion, jalapeno, lime juice, salt, and pepper in a bowl. Mash to combine ingredients, leaving avocados moderately chunky.
Heat flour tortilla one at a time in a skillet on high heat, flipping once. Alternatively, they can all be microwaved together for 10 seconds.
When beans are heated through, mash a few of them with a fork until the mixture thickens slightly.
Serve beans in tortillas, top with guacamole, cotija cheese, chopped tomatoes, and cilantro.