In a medium bowl, combine the chicken thighs with the olive oil, lime juice, chili powder, cumin, paprika, garlic powder, and onion powder. Season generously with salt and pepper. Toss until the chicken is thoroughly coated.

Let it marinate for at least 30 minutes at room temperature, or up to 4 hours in the refrigerator for maximum flavor penetration.

For the pico de gallo, combine the diced tomatoes, red onion, cilantro, and minced jalapeño in a small bowl. Squeeze the juice of one lime over the top, season with salt, and stir to combine.

For the guacamole, mash the avocados in a separate bowl, then stir in lime juice, salt, and a tablespoon of your pico de gallo for extra flavor. Set both aside.

Preheat your grill or cast-iron skillet over medium-high heat. Place the marinated chicken thighs on the grill and cook for 5-7 minutes per side, until cooked through (165°F / 74°C) and nicely charred.

Remove from the heat and let it rest for 5 minutes before chopping it into small, bite-sized pieces.

Warm the corn tortillas one by one on a hot, dry skillet for about 30 seconds per side until they are soft and fragrant.

To build your tacos, lay a warm tortilla flat and fill it with a generous portion of the chopped grilled chicken. Top with pico de gallo, a sprinkle of diced red onion, fresh cilantro, and crumbled cotija cheese. Finish with a dollop of guacamole right on top.