Spread the potatoes over the bottom of a slow cooker and top with the pork.
In a large bowl, mix the (undrained) tomatoes with the chipotles, adobo sauce, Worcestershire, oregano, garlic, onion, and about 1.5 tsp. salt. Pour the mixture evenly over the meat and potatoes.
Cover and slowcook on high for 6 hours or low for 10(ish).
When you’re ready to eat, fry the optional chorizo and then stir everything together, breaking the pork into smaller pieces. Taste and season with additional salt if necessary.
Note: If you used the Instant Pot, follow the instructions above and set the cook mode to meat. This mode defaults to 35 minutes. Do a quick release. Add the fried chorizo and conbine, then set the Instant pot for an additional 15 minutes. Either quick release or allow the steam to release on it's on. Serve with warm tortillas, cheese, and avocados. Enjoy!