In a large skillet, heat the vegetable oil over medium heat.

Add the onion and garlic and cook until softened, about 5 minutes.

Add the pork shoulder and cook until browned on all sides.

In a small bowl, combine the chili powder, paprika, cumin, oregano, cayenne pepper, salt, and black pepper. Sprinkle the spice mixture over the pork.

Pour in the chicken broth and lime juice. Stir to combine.

Transfer the mixture to a slow cooker and cook on low for 4 hours.

When ready to serve, heat the corn tortillas in a dry skillet or on a grill pan.

Fill each tortilla with the spicy pork mixture and top with chopped cilantro, diced onion, crumbled queso fresco, and sliced avocado.

Serve immediately and enjoy!