Port Wine Reduction Mushroom Swiss Burger with Caramelized Onions

Ingredients

• 1 1/2 pounds ground beef, 80/20
• 1 teaspoon salt
• 1/2 teaspoon black pepper, freshly ground
• 2 tablespoons unsalted butter
• 2 tablespoons olive oil
• 2 yellow onions, thinly sliced
• 1/2 teaspoon sugar
• 8 ounces cremini mushrooms, sliced
• 2 cloves garlic, minced
• 3/4 cup port wine
• 1/2 cup beef stock
• 1 teaspoon fresh thyme leaves
• 4 slices Swiss cheese
• 4 hamburger buns, split
• 1 tablespoon olive oil, for toasting buns

Method

1. 1

   Heat 1 tablespoon olive oil and 1 tablespoon butter in a 9-inch skillet over medium-low heat. Add the sliced onions and sugar, and cook, stirring occasionally, until deeply golden and caramelized.

   30:00 · Caramelize onions
2. 2

   Transfer the caramelized onions to a bowl and set aside. Wipe out the skillet.

3. 3

   In the same skillet, melt the remaining 1 tablespoon butter with 1 tablespoon olive oil over medium-high heat. Add the mushrooms and cook, stirring occasionally, until browned and tender.

   7:00 · Sauté mushrooms
4. 4

   Add the garlic and thyme to the mushrooms and cook until fragrant, about 30 seconds.

   0:30 · Cook garlic
5. 5

   Pour the port wine into the skillet and bring to a simmer, scraping up any browned bits. Simmer until the liquid is reduced by about half.

   5:00 · Reduce port wine
6. 6

   Add the beef stock and continue to simmer until the sauce is syrupy and coats the mushrooms. Season with a pinch of salt and pepper, then remove from heat and cover to keep warm.

   5:00 · Reduce sauce
7. 7

   Divide the ground beef into 4 equal portions and shape into patties slightly wider than the buns, pressing a shallow dimple in the center of each. Season both sides with salt and pepper.

8. 8

   Heat a clean 9-inch skillet or griddle over medium-high heat. Cook the patties until a deep crust forms on the bottom, about 4 minutes.

   4:00 · Sear first side
9. 9

   Flip the patties and cook until the internal temperature reaches 160°F, about 3 to 4 minutes more. During the last minute, top each patty with a slice of Swiss cheese to melt.

   3:00 · Finish cooking patties
10. 10

    While the patties finish cooking, brush the cut sides of the buns with olive oil and toast in a separate skillet or under the broiler until golden.

    2:00 · Toast buns
11. 11

    Assemble the burgers on the toasted buns with the cheese-topped patties, a generous spoonful of caramelized onions, and a layer of the port wine mushrooms. Serve immediately.