Set a large heavy duty dutch oven over medium-high heat with the oil. Once hot, sear the steak on both sides until browned, about 2 to 4 minutes on each side. Transfer the steak to a plate or platter and set aside. Stir in onion, bell peppers, garlic and tomatoes and cook until just beginning to soften, about 5 minutes. Return the steak to the pot with the veggies and add in the bay leaves, tomato paste, tomato sauce, chicken stock, salt, pepper, cumin, paprika, oregano, and crushed red pepper flakes. Reduce the heat to low, cover and simmer stirring occasionally, about 45 minutes. Stir in the capers, cover the pot once more and cook until the beef shreds easily with a fork, about 1 hour to 1 hour and half. If the liquid dries out, try adding in a bit of water if needed.

Carefully transfer the meat to a cutting board and shred with two forks. Return to the sauce and veggies.

To assemble the sliders, split the rolls in half and spread the bottom halves with refried beans and the top half with mashed guacamole. Top the bottom half with the shredded beef and veggies, draining the liquid as best you can. Then sprinkle the guacamole half with queso fresco. Sandwich together and skewer with a long toothpick to hold in place. Enjoy!