Preparation Melt butter with oil in heavy medium skillet over medium-high heat. Add sea bass to skillet; cook just until opaque in center, about 4 minutes per side. Transfer fish to plate; tent with foil to keep warm. Pour off all but 1 teaspoon drippings from skillet. Add shallots to same skillet; stir 30 seconds. Add Vermouth; bring to boil. Continue to boil 1 minute. Add cream; boil until sauce thickens slightly and coats spoon, about 3 minutes. Add 3/4 cup watercress to sauce. Season with salt and pepper. Transfer fish to plates. Spoon sauce around fish. Sprinkle with remaining 1/4 cup watercress and serve.
Preparation Melt butter with oil in heavy medium skillet over medium-high heat. Add sea bass to skillet; cook just until opaque in center, about 4 minutes per side. Transfer fish to plate; tent with foil to keep warm. Pour off all but 1 teaspoon drippings from skillet. Add shallots to same skillet; stir 30 seconds. Add Vermouth; bring to boil. Continue to boil 1 minute. Add cream; boil until sauce thickens slightly and coats spoon, about 3 minutes. Add 3/4 cup watercress to sauce. Season with salt and pepper. Transfer fish to plates. Spoon sauce around fish. Sprinkle with remaining 1/4 cup watercress and serve.