1. Preheat broiler to high.
2. Heat a grill pan over medium-high heat; coat with cooking spray. Sprinkle chicken evenly with 1/4 teaspoon salt and 1/4 teaspoon black pepper; cook 5 minutes on each side or until done. Remove from pan; thinly slice.
3. Combine peas, parsley, 3 tablespoons oil, 2 tablespoons water, and garlic in a small saucepan. Bring to a simmer; cook 2 minutes. Place pea mixture, rind, 1 tablespoon juice, remaining 1/4 teaspoon salt, and red pepper in a mini food processor; process until smooth.
4. Broil bread slices 1 minute on each side or until toasted. Combine arugula, remaining 1/2 teaspoon oil, and remaining 1/2 teaspoon juice. Spread pea mixture evenly over bread slices; top with arugula mixture and chicken. Sprinkle with Parmesan cheese and remaining 1/4 teaspoon black pepper.