Heat 1 tbsp olive oil in the Instant Pot on saute mode. When hot, add onion, garlic and tomato, sauteeing for 5 minutes until softened. Add chipotles, spices and salt & pepper, sauteeing another minute until fragrant.
Add mixture to a blender and blend with beef broth and apple cider vinegar until combined.
Meanwhile, season beef chunks generously with sea salt and heat remaining 2 tbsp olive oil in the Instant Pot. Add beef when oil is hot, cooking for 2 minutes per side until a nice sear develops.
Add the blended sauce and cinnamon, then turn off saute mode. Cook on high pressure for 45 minutes then let the pressure naturally release.
Remove lid once safe to do so, then remove beef from the Instant Pot and shred with 2 forks. Remove cinnamon stick if using. Finally, remove 2 cups of the sauce, then add beef back to the pot.
Heat a large skillet over med-high heat, then lightly coat each corn tortilla in the fat floating on top of the reserved sauce. Add a bit more olive oil to the skillet, then add 2 corn tortillas at a time, cooking on one side (do not flip!) for 1-2 minutes until lightly toasted.
Fill each with a bit of beef, topping with cheese. Fold corn tortilla over, then fry for 2 minutes per side.
Remove each tortilla from heat, then sprinkle with diced raw onion, cilantro and lime wedges. Serve by dipping in reserved sauce and enjoy!