Ingredients

• 1 1/2 pounds beef tenderloin, well trimmed, meat cut bite-sized pieces (about 1-inch square)
• 4 tablespoons butter
• 1/2 cup finely chopped shallots 2 1/2 cups sliced mushrooms
• 2 cups canned beef broth
• 3 teaspoons cornstarch
• 1 cup sour cream
• 2 teaspoons dijon mustard