1

Preheat the oven to 325° F. Fold four 20- by 12-inch sheets of heavy-duty foil in half crosswise, then open each sheet like a book and brush one "page" with 1 teaspoon of the melted butter, leaving a 2-inch margin all around.

2

Bring a large saucepan of water to a boil over high heat. Add the noodles and carrots and cook, uncovered, stirring occasionally, for 5 minutes or until almost tender. Drain well and toss with the cream and half of the scallions, dill, salt, and pepper.

3

Divide the noodle mixture evenly among the 4-buttered foil "pages" and top each with 1/2 cup of the watercress, then a fish fillet. Spoon on the remaining butter and sprinkle with the remaining scallions, dill, salt, and pepper.

4

Fold the foil over, enclosing the food, and seal the edges by folding over twice. Place the foil packets on a baking sheet and bake for 15 minutes. To serve, slit the foil and slide the fish, noodles, and vegetables onto serving plates.