In a food processor, combine onion, garlic, chipotles, cumin, oregano, ground cloves, lime juice, apple cider vinegar, and beef broth (or water, or beer). Blend until pureed.
Season the beef portions with salt and pepper.
Press on SAUTE on the Instant Pot, and heat vegetable oil. Sear the roasts (in 2 batches) until brown on all sides. Switch off the saute setting, and deglaze the pot with 2 tablespoons of water scrubbing any stuck bits to the bottom of the pot with a wooden spatula or spoon.
Add the beef back in, cover with the pureed sauce and add the bay leaves. Give everything a quick stir so that the meat is covered in the sauce.
Secure the lid and set the vent to SEALING. Select the PRESSURE COOK/MANUAL setting and set the cooking time for 60 minutes at high pressure. The Instant Pot will take around 7-8 minutes to come to pressure and start cooking. When the cooking program ends, quickly release the steam.
Carefully remove the lid, discard the bay leaves, and take the beef out to shred.
Shred the meat using 2 forks, then put it back in the Instant Pot in the sauce to soak it up.
Strain liquid from beef, and serve in tortillas with your favorite toppings.