While the grill heats, prepare your salsa to allow flavors to meld. Combine diced strawberries, diced red onion, minced jalapeno, and finely chopped cilantro in a bowl. Pour in the freshly squeezed lime juice, add the chili powder and ground cumin, and stir gently to combine. Set aside at room temperature—the acidity from the lime juice will lightly "cook" the strawberries while you prepare the chicken. I find that letting salsa sit for even 5-10 minutes before serving brings all those bright flavors together beautifully.
Heat your grill to medium-high heat (around 400°F). Pat the chicken thighs dry with paper towels—this ensures better browning and crispier skin. Season both sides generously with the taco seasoning, kosher salt, and black pepper, rubbing it in so it adheres well. Place chicken skin-side down on the grill and cook for 3-4 minutes until golden brown, then flip and cook for another 3-4 minutes until the internal temperature reaches 160°F. The skin-down start creates a flavorful crust that holds the seasoning beautifully.
Remove the grilled chicken from the heat and place it on a cutting board to rest for 5 minutes—this allows the juices to redistribute throughout the meat, keeping it tender and moist. While the chicken rests, place the corn tortillas directly on the grill grates for 30 seconds per side to warm and char them lightly. Stack the warm tortillas in a clean kitchen towel to keep them soft and pliable until serving.
After resting, slice the chicken thighs into strips, keeping the skin intact for texture. Lay out a warm tortilla and build each taco by arranging shredded lettuce as the base, topping with a strip of chicken, then sprinkling with cheddar cheese and sliced avocado. Finish with a generous spoonful of the strawberry salsa from Step 1, allowing the juices to drip onto the tortilla. Serve immediately while the tortillas are still warm and the salsa is bright and fresh.