In a bowl, combine lime juice, olive oil, minced garlic, cumin, chili powder, salt, and pepper, then add chicken breasts and coat well with the marinade. Cover and refrigerate for 1-4 hours so the chicken absorbs the citrus flavors (visual cue: the chicken looks evenly coated).

After marinating, remove the chicken from the refrigerator and let it sit at room temperature while you preheat the grill. This helps the surface cook evenly, aiming for a grill-ready heat level (visual cue: chicken looks slightly less chilled).

Place chicken on the preheated grill and cook for 6-7 minutes per side until cooked through. Flip once; avoid pressing so juices stay in (visual cue: grill marks appear and juices run clear).

Transfer grilled chicken to a plate, then top each piece with sliced avocado and pico de gallo. Add the toppings right after grilling so the chicken stays hot under the fresh mixture (visual cue: avocado sits on top in neat slices).

Garnish with cilantro and serve with lime wedges on the side. Finish at the last moment so herbs look bright and fresh (visual cue: cilantro is loosely scattered and lime wedges are visible).