Beef Stroganoff with veal

2 cups beef stock prefer veal stock if possible 1 pound beef round steak thinly sliced 2 tablespoons butter 3 tablespoons olive oil 1 each onion, yellow[...]

1 1/2 pounds beef, tenderloin or sirloin, cut in 2 by 1 inch strips 1/2 teaspoon salt 1/4 teaspoon black pepper * 1 each onion cut in 1/4 inch slices 4[...]