Preheat oven to 375°F. Place spinach in a heavy nonstick skillet over medium high heat. Cover and cook 4-5 minutes, stirring occasionally, or until spinach is wilted and tender. Transfer to a colander. Press out excess liquid. Chop spinach and return to skillet over medium heat. Add next 5 ingredients and salt and pepper to taste. Simmer 10-12 minutes, stirring frequently, or until cream cheese is melted and mixture is hot. Set aside and keep warm. Arrange fish fillets in a baking dish. Season with tarragon, salt and pepper to taste. Bake 12-15 minutes or until fish flakes easily. Serve spinach sauce over fish fillets.
