Put all the ingredients for the sauce in a bowl and mix together.
Trim the lamb shoulder of large pieces of fat and cut into large pieces. Place in a lidded container.
Rub the sauce over the lamb and place in the fridge overnight.
Transfer the lamb and marinade in the Instant Pot. Rinse the container out with pineapple juice and add.
Cook for 35 minutes at high pressure and leave pressure to release naturally.
Transfer the lamb to a platter and use two forks or shredding claws to shred the meat. Add some of the sauce and toss together.
Taste and check the seasoning is to your liking, adding more salt and pepper if needed.
To serve
Heat the tortillas up in a pan (or your toaster, but watch they don’t burn!). Spread a generous amount of shredded lamb on each. Add pineapple and avocado slices. Top with coriander and sliced onion and some hot sauce, if you like. Serve with lime wedges on the side.
How to make lamb al pastor in a slow cooker
Follow steps 1-3. Put the marinated lamb and pineapple juice (please note you will need 1 cup /250ml) in your slow cooker and cook on low for 8 hours, or on high for 4-5 hours, until the lamb is completely tender and falls apart at the touch of a fork.
Video
Notes
You can use Chipotle en Adobo paste instead of chilli paste (available at Waitrose and Ocado in the UK).
Serving suggestions
While the lamb is delicious served as tacos, it is also lovely over rice or in a salad.
For a lighter version
Skim any fat from the sauce – put in the fridge and discard the fat which will solidify on the surface of the sauce.
For those following Slimming world (as I am currently) serve your lamb al pastor on crunchy lettuce leaves instead of tortillas and replace the avocado witch chopped tomatoes.
Nutritional information is always approximate, and will depend on ingredients you choose.