Cut chuck roast into large chunks. Season with kosher salt.
Instant Pot Method: set IP to saute mode and add in about 1 tbsp of avocado oil. Once hot, add the chuck roast pieces and brown on each side for 2-3 minutes.
While chuck roast is browning, in a large bowl, add in diced tomatoes, Noble Made Hot & Spicy Marinade, diced jalapeño chiles, chopped onion, minced garlic, chili powder, cumin, and bone broth. Mix until well combined.
Turn IP off from saute mode, add the mixture to IP, close the IP, seal it, and cook on high pressure for 70 minutes. Once done, let it naturally release for 10 minutes before removing the lid.
Slow Cooker Method: preheat a cast iron skillet over medium-high with avocado oil. Once hot, brown the chuck roast on all sides for 2-3 minutes.
Once browned, add chuck roast to slow cooker, and the remaining ingredients. Cook on low for 8-10 hours or high for 4-6 hours.
Remove chuck roast from IP or slow cooker, shred with two forks.
Cut off the ends of plantains then cut the plantains into 2 inch chunks.
Cut the 2 inch chunks lengthwise and then remove the skin.
Preheat a large skillet over medium heat with enough coconut oil to cover the skillet.
Add plantains to skillet and fry for 3-4 minutes per side or until lightly browned and cooked through.
Remove plantains from skillet, lay on a flat surface, and then flatten plantains with a flat bottom object (i.e. plate, small skillet, bottom of a cup, and etc).
In the same skillet (add more oil if you need to), add the flatten plantains to the skillet and cook on both sides for 2-3 minutes or until golden brown.
Drain and immediately salt the plantains.
Serve the shredded beef on top of the "tostadas" and add your favorite toppings (i.e. guacamole, pico de gallo, sour cream, finely diced onions, and etc)