In a mixing bowl, combine olive oil, lemon juice, garlic, cumin, paprika, salt, and black pepper. Add the chicken breasts and coat well. Cover and marinate in the refrigerator for at least 30 minutes.

Preheat the grill to medium-high heat. Remove the chicken from the marinade and discard the marinade.

Place the chicken on the grill and cook for 6-8 minutes per side or until the internal temperature reaches 165°F (75°C).

While the chicken is grilling, prepare the avocados. Once cooked, remove the chicken from the grill and let it rest for a few minutes.

Slice the grilled chicken and serve topped with sliced avocados, chopped cilantro, and lime wedges. Add a dollop of sour cream on the side.