1In 10-inch skillet, melt butter over medium-high heat. Cook leeks and carrots in butter 3 minutes, stirring frequently, until softened.
2Mound vegetable mixture into 4 piles in skillet. Place 1 piece of fish on each mound. Pour corn over fish. Reduce heat to medium-low. Cover; cook 10 minutes or until fish flakes easily with fork. Serve with lemon wedges.