In a medium piece of cheesecloth, combine cumin seeds, black peppercorns, cloves, Mexican oregano, and thyme. Gather the edges, tie securely with kitchen string, and enclose all the spices.

Pat the meat dry with paper towels to remove excess moisture. If using brisket, slice it in half for thinner pieces.

Return all meat to the pot. Pour in 8 cups of water (or enough to cover the meat). Add the spice sachet and aromatics: white onion, head of garlic, ground guajillo, Mexican cinnamon, and apple cider vinegar.

Lock the lid and cook on High Pressure for 1 hour. Let pressure release naturally for 10 minutes, then manually release any remaining pressure. Turn off the Instant Pot.

Using the same skillet with residual fat, add the shredded meat over medium heat. Let the edges crisp up, spooning in 2–3 ladles of broth as needed to keep it juicy.

Taste and adjust salt, then turn off the heat.

Fill each tortilla with a generous amount of the crisped meat. Top with onion, cilantro, salsa verde, a squeeze of fresh lime juice, pickled jalapeños, and serve spring onions on the side.