Instructions: Pour one recipes worth of Mushroom Essence through a fine strainer into a 4- to 5-quart pan; discard the ginger. Put mushrooms in a shallow 10- to 11-inch oval casserole (about 2 1/2 quarts). Add green onions, capers, sherry, soy sauce, and ginger to mushrooms; mix and spread level. Lay fillets evenly over mixture, overlapping if necessary. Cover casserole tightly with foil.

Bake fish in a 375 degree oven until fillets are opaque but still moist-looking in center of thickest part, about 15 minutes; keep warm.

While fish bakes, add potatoes and tarragon to mushroom broth. Bring to a boil over high heat; cover and simmer until potatoes are soft enough to mash easily, about 15 minutes. Drain potatoes in a strainer over a bowl. Pour liquid back into pan and put potatoes in the bowl.

Uncover fish and drain juices into pan. Boil liquid over high heat until reduced to about 3/4 cup, 4 to 5 minutes. In a small bowl, blend cornstarch with 1 tablespoon water and stir into boiling liquid; stir until boiling again, and remove from heat. Turn oven to broil.

Meanwhile, with a potato masher or a mixer, mash potatoes until smooth, adding enough milk for desired texture. Push fish and mushrooms toward center of casserole to leave a 1-inch space around the edge. Spoon potatoes (or pipe through a pastry bag with a large plain or star tip) into space. Pour sauce over fish mixture. Sprinkle potatoes with cheese.

Broil about 4 inches from heat until cheese is very lightly browned, about 4 minutes. Sprinkle with remaining 1/4 cup green onions. Add salt and pepper to taste.

This recipe yields 4 servings.

If you would like to email yourself the recipe for later use, or share the recipe with your friends or family, enter the email addresses below and this recipe will be emailed to you and others as well.