- Combine chicken stock, soy sauce, crushed pineapple, chili powder, cumin, chipotle peppers and garlic cloves in a blender or food processor and blend until smooth.
- Place pork roast in instant pot and cover with sauce. Secure lid and close vent valve. Press manual setting for 45 minutes.
- When the timer goes off, allow pressure to release for 5 minutes. Open vent valve and release any additional pressure. Remove lid and use tongs to transfer pork roast to a cutting board. Rest pork roast for 5 minutes. Cube meat into bite sized pieces and return to sauce in pot. Stir to coat.
- Spoon al pastor meat over tostadas topped with salsa or pico de gallo and jalapeño slices. Serve with lime wedges.