Pat your chuck roast dry and sprinkle both sides of beef with pepper. Turn on saute and add the 1 tablespoon of oil then sear both sides of chuck roast for 2-3 minutes on each side.
Remove beef from the instant pot and cut the beef into 6 large chunks. It will still shred, this just helps the beef cook faster. With it still on the saute setting, add the other tablespoon of oil and melt in the pan. Add garlic, grated ginger, sesame oil, onion, 1/4 cup coconut aminos (or soy sauce), and maple syrup to the instant pot. Mix well and place the chuck roast back on top of the sauce ingredients.
Close the lid of the instant pot and seal the pressure gauge. Set the Instant pot to manual (or pressure cook) on high pressure and cook for 45 minutes. You can also leave the roast whole and cook on low pressure for 2 hours.
In the 30 minutes before the beef is done cooking, make the sriracha mayo. Mix all of the sriracha mayo ingredients together in a small bowl, cover and leave in the fridge until ready to use.
When the beef is done cooking, you can either naturally release or quick release the pressure. Natural release is preferred, but if you’re short on time quick release is a great option. For natural release, don’t do anything when the time is up and just let the pressure cooker release the pressure naturally, which can take 5-30 minutes. You’ll know when the nozzle clicks and the lid unlocks. To quick release, carefully turn the knob to let the jet of steam out to release the pressure quickly. Once the pressure it released, carefully remove the roast and place on a cutting board.
In a small bowl or measuring cup, mix together the tapioca starch or cornstarch with the remaining 1/4 cup coconut aminos (or soy sauce) until dissolved. Turn the instant pot back to saute mode and add the tapioca starch mixture to the sauce and stir until thickened, 2-3 minutes. Add the beef back to the thickened sauce and shred using two forks. Close the lid and place back on warm setting while you assemble the taco ingredients.
Serve korean beef in warm tortillas topped with chopped cilantro, diced red onion, sesame seeds, avocado, kimchee or sriracha mayo.
Also serve with a batch of skinny margaritas for the perfect date night! See recipe notes for easy margarita recipe.