To prepare gremolata, place mint, pine nuts, rind, and garlic in a mini chopper; process just until combined. Add 4 teaspoons olive oil and 1/4 teaspoon salt; process to combine. Set aside.
To prepare chicken, heat a large grill pan over medium-high heat. Brush 2 teaspoons olive oil evenly over chicken; sprinkle chicken evenly with 1/2 teaspoon salt and pepper. Add chicken to pan; cook 5 minutes on each side or until done. Remove chicken from pan; let stand 5 minutes. Serve gremolata with chicken.