Prep all ingredients per the instructions above.

Heat the olive oil in a large skillet over medium-high heat. Sear the beef on all sides until browned, then transfer to a slow cooker.

Deglaze the skillet with a small amount of beef broth or water, scraping up any browned bits, and add this liquid to the slow cooker.

Add the onion, garlic, paprika, chili powder, chipotle sauce if using, oregano, ground cumin, bay leaf, beef broth, apple cider vinegar, lime juice, salt, and black pepper to the slow cooker. Stir to combine.

Cover and cook 3 - 5 hours on high or 6 - 8 hours on low until the beef is fork-tender and easily shredded. Shred the beef with two forks and stir it back into the cooking liquid.

Preheat the oven to 350°F (177°C) and line a baking sheet with parchment paper.

Mash the banana in a bowl until smooth. Stir in the vanilla extract and cinnamon, then fold in the oats until evenly coated. Gently mix in the dark chocolate chips. Scoop the dough onto the prepared baking sheet and lightly flatten. Bake for 12–15 minutes, until set and lightly golden. Let cool for 5 minutes before serving.

Mash the avocado in a bowl. Stir in the cilantro, garlic, lime juice, and salt to taste.

Warm the taco shells in a dry skillet until soft and pliable.

Fill the taco shells with the shredded beef and top with cheddar cheese, tomato, and jalapeño if using.

Serve the tacos with tortilla chips, guacamole, lemon sparkling water, and banana oatmeal cookies for dessert.