In a large mixing bowl, combine the chicken pieces with minced garlic, lime juice, oil, cumin, smoked paprika, salt, and black pepper. Ensure all chicken is coated well in the marinade, and reserve a portion of the marinade for later basting. Cover and marinate in the refrigerator for at least 1 hour, or overnight for deeper flavor.

Preheat your grill to medium-high heat or the oven to 450°F. Grill each piece of chicken for 5-7 minutes per side, basting with reserved marinade halfway through, or bake for approximately 30 minutes until internal temperature reaches 165°F.

Rinse the rice under cold water until the water runs clear, then soak for 10 minutes. Melt butter in a large saucepan over medium heat and sauté chopped onion until translucent. Add minced garlic and cook until fragrant, about 1 minute. Stir in the soaked rice, add chicken stock, and bring to a boil. Cover and reduce heat to low, cooking for 15 minutes.

Remove rice from heat and let it sit for 5 minutes, then fluff with a fork and stir in the frozen peas.

In a blender, combine fresh cilantro, mayonnaise, sour cream, jalapeños (if using), garlic, olive oil, lime juice, and salt and pepper. Blend until smooth and creamy.

To serve, place a scoop of rice on each plate, top with grilled chicken, and drizzle with green sauce. Garnish with additional cilantro or scallions and lime wedges.