1. Place racks in upper-middle and lower-middle parts of oven and heat to 400 degrees. Coat both sides of tortillas with cooking spray or brush lightly with vegetable oil and season with salt and pepper. Divide tortillas over two baking sheets and bake until lightly browned and crisp, 8 to 10 minutes, flipping halfway through; transfer to a plate and set aside.
2. Place steak on a baking sheet and reheat in oven until warmed through, about 5 minutes.
3. Meanwhile, transfer 2 tablespoons black bean liquid to a medium heatproof bowl, then drain beans. Add beans, marinade, and lime juice to bowl and microwave until hot, 1 to 2 minutes. Mash until beans are mostly smooth and spreadable, then cover to keep warm and set aside.
4. To serve, arrange two toasted tortillas on each plate and spread black bean mixture over top. Slice steak thinly against the grain and divide over tostadas, then top evenly with salsa, avocado, and cilantro. Serve with lime wedges.
Source: Hannaford fresh Magazine, May - June 2020