Beef Stroganoff

5 cups sliced fresh mushrooms
1 large onion, sliced
1 tablespoon butter
1/3 to 1/2 cup hot water
1 tablespoon prepared horseradish
1/2 teaspoon salt
1/8 teaspoon pepper
1/4 cup all-purpose flour
1 beef flank steak (1-1/4 pounds), cut into 2-inch strips
1 cup (8 ounces) sour cream
Hot cooked noodles

In a large skillet, saute mushrooms and onion in butter until tender. With a slotted spoon, transfer to a bowl; stir in the water, horseradish, salt and pepper. Set aside.

Place flour in a large resealable plastic bag. Add beef, a few pieces at a time, and shake to coat. In the same skillet, brown beef in batches. Return all of the beef to the pan; top with mushroom mixture.

Bring to a boil. Reduce heat; cover and simmer for 1-1/4 to 1-1/2 hours or until beef is tender, stirring once. Remove from the heat; stir in sour cream. Serve with noodles. Makes 6 servings.