In a bowl, mix olive oil, lime juice, garlic powder, cumin, salt, and pepper.
Coat chicken breasts evenly and let marinate for at least 15 minutes (or up to 2 hours).
Combine diced tomatoes, red onion, cilantro, jalapeño, lime juice, and salt in a bowl.
Refrigerate until ready to use.
Blend sour cream, mayonnaise, cilantro, lime juice, garlic, and salt until smooth.
Chill until serving.
Preheat grill or grill pan to medium-high heat.
Cook chicken for 6-7 minutes per side, until internal temperature reaches 165°F.
In the last minute, top each breast with a slice of pepper jack cheese to melt.
Place grilled chicken on a plate.
Top with pico de gallo and drizzle with cilantro lime sauce.
Serve with warm tortillas, rice, or a side salad.