1 cup basmati rice, rinsed
1/2 cup frozen peas
3/4 cup plain yogurt
1 small clove garlic, chopped
1 1-inch piece ginger, peeled and chopped
1 tablespoon fresh lime juice, plus lime wedges for serving
1/4 teaspoon ground cumin
1/4 teaspoon cayenne pepper
4 6-ounce tilapia fillets
2 tablespoons unsalted butter, melted
1 tablespoon chopped fresh cilantro or mint
Bring the rice, 1 1/3 cups water and 1/4 teaspoon salt to a simmer in a saucepan over medium-high heat.
Reduce the heat to low, cover and cook 15 minutes. Remove from the heat and add the peas; cover and set aside.
Puree 1/2 cup yogurt, the garlic, ginger, lime juice, cumin, cayenne and 3/4 teaspoon salt in a food processor. Transfer all but 3 tablespoons of the mixture to a large bowl.
Pierce the fish a few times with a fork and season with salt; add to the bowl and toss. Marinate 15 minutes
Preheat the broiler. Place the fish on a broiler pan; top with the marinade and butter. Broil until opaque, 6 to 8 minutes.
Mix the remaining 1/4 cup yogurt, the cilantro, and salt to taste with the yogurt mixture.
Serve the fish and rice with the yogurt sauce and lime wedges.