Preparing Smoky Chipotle Chicken Tacos is a straightforward process that involves marinating, cooking, and assembling. Follow these steps to create this delicious dish:

Step 1: Prepare the Marinade

1. In a mixing bowl, combine the chopped chipotle peppers, minced garlic, lime juice, olive oil, cumin powder, oregano, salt, and black pepper.
2. Mix well until all ingredients are thoroughly combined.

Step 2: Marinate the Chicken

3. Place the chicken thighs or breasts in a large resealable plastic bag or a shallow dish.
4. Pour the marinade over the chicken, ensuring each piece is well-coated.
5. Seal the bag or cover the dish and refrigerate for at least 1 hour, preferably overnight, to allow the flavors to infuse the chicken.

Step 3: Cook the Chicken

6. Preheat a grill or a skillet over medium-high heat.
7. Remove the chicken from the marinade and discard any excess marinade.
8. Grill or cook the chicken for 6-7 minutes on each side or until fully cooked and the internal temperature reaches 165°F (75°C).
9. Once cooked, transfer the chicken to a cutting board and let it rest for a few minutes before slicing into thin strips.

Step 4: Assemble the Tacos

10. Warm the taco shells in a dry skillet or microwave until pliable.
11. Fill each taco shell with a portion of the sliced chicken.
12. Top with sliced red onion, chopped cilantro, avocado slices, a dollop of sour cream, and crumbled Cotija cheese.
13. Add any optional toppings of your choice, such as diced tomatoes, shredded lettuce, or jalapeños.