Slow-Cooked Carnitas Tacos

This is my all time favorite taco recipe. It's super simple and tasty.

Ingredients:
2 pounds boneless country-style pork ribs or pork shoulder, cut into 1 1/2-inch pieces
2 teaspoons salt
2 teaspoons ground black pepper
2 teaspoons dried oregano (preferably Mexican)
1/2 large onion, cut into 4 pieces
1 avocado, halved, pitted, sliced
Fresh cilantro springs
Corn tortillas

Directions:
1. Toss pork in bowl of slow cooker with salt, black pepper, and dried oregano to coat. Place onion pieces atop pork. Cover slow cooker and cook pork on low setting until meat is very tender and falling apart, about 6 hours.
2. Using slotted spoon, transfer pork to cutting board. Discard onion pieces. Using fingers, shred pork; transfer carnitas to platter. Place avocado slices, cilantro sprigs, and sliced red bell peppers, if desired, alongside.
3. Wrap corn tortillas in damp kitchen towel; microwave until warm, about 1 minute. Serve carnitas with warm tortillas and tomatillo salsa.