1/2 cup chopped fresh mushrooms
1 tablespoon butter
2 teaspoons all-purpose flour
1/4 teaspoon pepper, divided
1/2 cup half-and-half cream
1 large egg yolk
2 tablespoons finely chopped onion
1/4 teaspoon salt
1/2 pound ground beef
1 tube (4 ounces) refrigerated crescent rolls
Large egg, lightly beaten, optional
1 teaspoon dried parsley flakes
In a saucepan, saute mushrooms in butter until softened. Stir in flour and 1/8 teaspoon pepper until blended. Gradually add the cream. Bring to a boil; cook and stir until thickened, about 2 minutes. Remove from the heat and set aside.
In a bowl, combine the egg yolk, onion, 2 tablespoons mushroom sauce, salt and remaining 1/8 teaspoon pepper. Crumble beef over mixture and mix well. Shape into 2 loaves. Separate crescent dough into 2 rectangles on a baking sheet. Seal perforations. Place a meat loaf on each rectangle. Bring dough edges together and pinch to seal. If desired, brush with egg wash. Bake at 350° until golden brown and a thermometer inserted into meat loaf reads 160°, 24-28 minutes.
Meanwhile, warm remaining sauce over low heat; stir in parsley. Serve sauce with Wellingtons.