Directions

1. Add flank steak, onions, garlic, bay leaf, sea salt, and fresh ground black pepper to pressure cooker.
2. Close and lock lid, set pressure cooker to "meat/stew", adjust for 20 minutes, and press "start/stop".

3. When done, quick release and make sure all pressure is released before opening lid. Carefully open lid and remove bay leaf. Remove beef and shred with forks; set aside.

4. In a bowl, mix shredded beef, red onions, tomatoes, avocado, queso fresco, cilantro, lettuce, oregano, cumin, sea salt, ground black pepper, and olive oil. Toss well. Serve on tostadas and top with sour cream.