Preheat your grill to medium-high heat, around 400°F (200°C). This temperature is ideal for grilling chicken and achieving those beautiful grill marks.

In a mixing bowl, combine olive oil, lime juice, minced garlic, chili powder, cumin, salt, and black pepper. Whisk until well blended.

Place the chicken breasts in a large resealable plastic bag or shallow dish. Pour the marinade over the chicken, ensuring each piece is well coated. Seal the bag or cover the dish and refrigerate for at least 30 minutes, allowing the flavors to infuse.

While the chicken is marinating, prepare the avocados. Scoop out a bit of the flesh to create a small well in each half, making space for the cheese. Brush the avocado halves lightly with olive oil and set aside.

Once the chicken has marinated, remove it from the refrigerator and let it sit at room temperature for about 10 minutes before grilling. This helps the chicken cook more evenly.

Place the marinated chicken on the preheated grill. Grill for about 6-7 minutes on each side, or until the internal temperature reaches 165°F (75°C). Avoid flipping the chicken too often to achieve nice grill marks.

In the last few minutes of grilling, place the avocado halves on the grill, cut side down. Grill for 2-3 minutes until they are slightly charred and warmed through.

Once the chicken is fully cooked, remove it from the grill and let it rest for 5 minutes. This resting period allows the juices to redistribute, ensuring a moist chicken.

To serve, place each grilled chicken breast on a plate and top with a grilled avocado half. Fill the well with shredded mozzarella cheese and sprinkle with fresh cilantro for garnish. Enjoy!