PREHEAT oven to 425°F. Salsa Verde: HALVE the pasilla pepper (remove seeds if you don’t like spicy), remove the husks from the tomatillos. Place tomatillos and pepper on a baking sheet. Roast for 15-20 minutes, flipping everything once about halfway. Remove from the oven and place in a food processor along with the remaining salsa verde ingredients. Pulse until a salsa-like consistency is reached.
SOUP: Start the sauté mode on the Instant Pot. Once hot, add the ghee and sauté the diced onion and pepper for 2-3 min, until slightly softened. Add the sirloin and spices. Continue sautéing for 3-4 min, until the beef is browned. Add the beef stock, water, and salsa verde. You may add the cauliflower at this point to save time, but it will be very soft after done.
COVER the Instant Pot and set for 12 minutes on high pressure. Quick release the pressure when finished. If you have not yet added the cauliflower, do so now, and set to manual high pressure for 2 min. Release the pressure when done. Ladle into two bowls and top with cilantro, avocado, sour cream, and lime wedges.
Alternate Stove Top Directions
DO steps 1-4 as above, then use a large deep pan or pot to start step 5. At step 7, follow directions but simply simmer the soup stove-top for 20 minutes or so until meat in soup is tender.