Combine basmati rice, chicken stock, coconut milk, and 1/2 teaspoon kosher salt in a medium saucepan; bring to a boil. Reduce heat to low. Cover; cook until liquid is absorbed, 14 to 16 minutes.
Meanwhile, cook ground chicken, red onion, and red bell pepper in 1 tablespoon canola oil in a large skillet over medium-high heat until chicken is cooked through, 5 to 6 minutes. Stir in soy sauce, jerk seasoning, chopped garlic cloves, and fresh ginger. Cook until fragrant, 1 minute. Fold in mango and cilantro. Season with kosher salt and black pepper. Serve rice and chicken mixture in butter lettuce leaves.