Marinate the Chicken: In a medium mixing bowl, combine the chicken pieces with the olive oil, lime juice, chipotle paste, smoked paprika, cumin, oregano, garlic powder, onion powder, cayenne (if using), salt, and pepper. Stir everything together until the chicken is thoroughly coated. Set aside to marinate for at least 15 minutes at room temperature.

Prepare the Toppings: While the chicken is marinating, prepare your toppings. Dice the avocado and red onion, and chop the coriander. Place them in separate small bowls, ready for assembly.

Heat the Pan: Place a large frying pan or skillet over a medium-high heat. Let it get properly hot – this is crucial for getting a good sear. You shouldn't need to add any extra oil as there is already some in the marinade.

Cook the Chicken: Add the marinated chicken to the hot pan in a single layer. It’s important not to overcrowd the pan, so you may need to do this in two batches. Cook for 4-5 minutes on the first side, undisturbed, until a deep brown crust forms. I find that leaving it alone is the best way to develop that beautiful char.

Finish Cooking: Flip the chicken pieces and cook for another 3-4 minutes on the other side, until cooked through and slightly charred in places. You can check if it's cooked by cutting into a larger piece. According to the Food Standards Agency (FSA), chicken should have no pink meat and be steaming hot inside. Remove the chicken from the pan and set aside on a plate.

Rest the Chicken: Let the chicken rest for a few minutes while you warm the tortillas. This helps the juices to redistribute, keeping the meat tender.

Warm the Tortillas: You can warm the tortillas by placing them directly over a low gas flame for a few seconds per side, or by wrapping them in foil and placing them in a warm oven (150°C/130°C fan) for 5-10 minutes. Alternatively, heat them in a dry frying pan for 30 seconds per side.

Assemble and Serve: To assemble your spicy chicken tacos, place a generous spoonful of the cooked chicken into each warm tortilla. Top with diced avocado, red onion, and a sprinkle of fresh coriander. Serve immediately with lime wedges and a dollop of soured cream on the side.