Cook English peas in boiling water with 1 teaspoon salt for 2 minutes. Drain and rinse with cold water; drain. Combine peas, 3 tablespoons oil, rind, juice, parsley, and shallots. Stir in 1/4 teaspoon salt and 1/4 teaspoon pepper; toss gently.
Heat a large cast-iron skillet over medium-high heat. Add 1 1/2 teaspoons oil to pan; swirl to coat. Sprinkle remaining 1/4 teaspoon salt and 1/4 teaspoon black pepper over scallops. Add half of scallops to pan; cook for 2 minutes on each side or until desired degree of doneness. Repeat procedure with remaining 1 1/2 teaspoons oil and scallops. Divide scallops evenly among 6 plates; top each serving with 2 1/2 tablespoons pea mixture and 1/4 cup pea shoots. Serve with lemon wedges.