Preheat oven to 425°. Line a large jelly-roll pan with foil.
Combine yogurt, 3 tablespoons lime juice, 1 tablespoon oil, curry powder, sugar, and garlic powder in a large bowl, stirring with a whisk. Add chicken leg quarters to yogurt mixture; gently toss well to coat. Let stand 30 minutes. Place chicken on prepared pan coated with cooking spray. Sprinkle chicken with 1/4 teaspoon salt.
While chicken stands, combine 1 tablespoon lime juice, remaining 2 1/2 tablespoons oil, 1/4 teaspoon salt, cilantro, cashews, mint, honey, rind, 1 teaspoon minced garlic, and onion in a small bowl; stir to combine. Set aside.
Place chicken in oven; bake at 425° for 35 minutes or until a thermometer inserted into thickest part registers 165°.
While chicken cooks, combine remaining 2 teaspoons garlic, stock, rice, and milk in a saucepan over medium-high heat; bring to a boil. Stir once to separate rice; cover, reduce heat, and simmer 40 minutes. Remove from heat; let stand 10 minutes. Remove lid; stir in remaining 2 teaspoons lime juice and remaining 1/4 teaspoon salt.
Divide rice among 4 plates; arrange 1 chicken leg quarter on top of each serving. Top evenly with cilantro mixture.