Blend the beef broth, lime juice, cider vinegar, chilis, cumin, oregano, and sea salt in a small blender and set aside.

Cut the beef roast into 4-6 large chunks.

Press the Saute button on the Instant Pot and add the oil. Once hot, carefully place the chunks of meat on the surface. Brown 2 minutes per side.

Pour the adobo sauce over the browned meat and secure the lid on the Instant Pot. Pressure cook on high for 60 minutes.

When the pot has finished its cycle and beeps, allow the pressure to naturally release. 

Remove lid and transfer the chunks of beef to a cutting board. Use 2 forks to shred the beef and place the meat back in the pot. Stir well and allow beef to sit 15 minutes or longer to absorb the juices. 

Serve barbacoa beef in tacos, burritos, or bowls.