Combine the salt, pepper, oregano, chili powder, cumin and cinnamon in a small bowl.
Rub this mixture on the pork shoulder.
Add the onion, garlic and jalapeno to the slow cooker.
Place the pork shoulder on top.
Pour the orange juice and beer around the pork in the slow cooker.
Cook on low for 8-10 hours or on high for 4-5 hours.
Once fork tender, remove the pork from the slow cooker, remove any fat, then shred the meat.
Heat the vegetable oil in a large pan over medium high heat.
Add the carnitas to the pan and cook for 4-5 minutes, or until slightly crispy.
Spread queso dip, refried beans or guacamole on warmed tostadas, then add the carnitas and toppings of your choice such as diced onion, fresh cilantro, salsa, queso fresco or guacamole.
Notes
Nutritional information provided does not include optional toppings.