Ingredients
1/2 cup milk (I used whole since I had it on hand from the mashed potatoes.)
7 tablespoons instant potato flakes
1 pound ground beef
Salt and pepper
4 tablespoons unsalted butter
1 onion, halved and sliced thin
1 pound white mushrooms, sliced thin
1 tablespoon tomato paste
2 tablespoons all purpose flour
1 3/4 cups beef broth
1/4 cup ruby port, tawny port or dry sherry (I used dry sherry, I haven’t even heard of those ports.)

Instructions
1. Whisk milk and potato flakes in large bowl. Add beef, 1/2 teaspoon salt, and 1/2 teaspoon pepper and knead until combined. Shape into 4 1/2-inch-thick oval patties and transfer to parchment-lined plate. Refrigerate for 30 minutes or up to 4 hours.

2. Melt 1 tablespoon butter in large nonstick skillet over medium-high heat. Cook patties until well browned, about 5 minutes per side. Transfer to plate.

3. Add onion and remaining butter to empty skillet and cook until onion is softened, about 5 minutes. Add mushrooms and 1/2 teaspoon salt and cook until liquid has evaporated, 5 to 7 minutes. Stir in tomato paste and flour and cook until browned, about 2 minutes. Slowly stir in broth and port (or sherry) and bring to simmer. Return patties to skillet, cover, and simmer over medium-low heat until cooked through, 12 to 15 minutes. Season sauce with salt and pepper. Serve. 



Comments
This recipe is from the 2007 Cook's Country Annual.  I don’t think I’ve ever had Salisbury steak before, so I thought it would be fun to try out.  I did goof while making the patties and made 6 instead of 4.  Oops.  I’m not entirely sure how I feel about this recipe yet.  The patties were very tender, but they weren’t very flavorful.  I also found the sauce to be a bit too thin, but I think I could fix that next time with a bit more flour and perhaps a short simmer of the sauce after removing the patties in the end. 

Shown here with French Mashed Potatoes with Cheese and Garlic (Aligot).