How to Make It
To prepare relish, place cucumber in a colander; sprinkle with 1/2 teaspoon salt. Toss well. Drain 30 minutes. Rinse and drain; pat dry.
Combine cucumber, chives, coconut, mint, cilantro, and jalapeño. Stir in 1/4 teaspoon salt, 2 tablespoons juice, and 1/2 teaspoon cumin. Heat 1 teaspoon oil in a small skillet over medium-high heat. Add mustard seeds; sauté 30 seconds or until seeds begin to pop. Add to cucumber mixture.
To prepare fish, combine rind, 1 1/2 tablespoons juice, 1 teaspoon oil, 1/2 teaspoon cumin, and crushed red pepper; rub evenly over cut sides of fillets. Sprinkle fillets with 1/4 teaspoon salt and black pepper.
Place fillets, skin sides down, on broiler pan coated with cooking spray; cook 7 minutes or until fish flakes easily when tested with a fork. Serve with relish and lime wedges.