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Rachael's A Burger To Love: Balsamic-Rosemary Cheese Burgers with Horseradish Sauce, Mushrooms and Onions

Rachael's A Burger To Love: Balsamic-Rosemary Cheese Burgers with Horseradish Sauce, Mushrooms and Onions


For the onions:

  • 2 tablespoons butter

  • 2 onions, chopped

  • Salt and fine black or white pepper

  • 1 bay leaf

For the mushrooms:

  • 3 tablespoons extra-virgin olive oil (EVOO)

  • 1 pound cremini mushrooms, sliced

  • 2 tablespoons fresh thyme, chopped

  • 4 large cloves garlic, chopped

  • Salt and pepper

  • ¼ cup sherry or ½ cup white wine

  • Juice of 1/2 lemon

For the burgers:

  • 8 slices meaty bacon

  • 1½ pounds (80/20) ground beef

  • 3 tablespoons grated onion

  • Salt and pepper

  • 2 tablespoons fresh rosemary, finely chopped

  • 2 cloves garlic, grated or pasted

  • 2 tablespoons Balsamic drizzle or aged Balsamic vinegar

  • 2 tablespoons extra-virgin olive oil (EVOO)

  • 8 slices fontina or mild provolone cheese

  • 4 burger buns, split

  • 4 slices beefsteak tomato

For the horseradish sauce:

  • ½ cup sour cream

  • ¼ cup aquafaba-based/chickpea mayo or mayonnaise

  • 2 tablespoons horseradish

  • 1 teaspoon black pepper

  • Juice of ½ lemon

  • ¼ cup finely chopped chives or scallions


Preheat oven to 375˚F.

For the onions, in a skillet over medium heat, melt butter, add onions and season with salt and pepper, add a bay leaf. Cook onions, low and slow, to light caramel color, 20-25 minutes. Add 1 cup water, and cook over low heat until liquid is completely absorbed, 10 minutes more.

Meanwhile, for the mushrooms, preheat a second skillet over medium-high heat, add EVOO, 3 turns of the pan, and add mushrooms to brown, 10-12 minutes. Add thyme, garlic, and salt and pepper, and cook 5 minutes more. Add sherry or wine, let it absorb completely, turn off the heat, then add lemon juice.

Arrange bacon on slotted pan or wire-rack lined baking sheet and bake until crisp, 12-15 minutes. Mix together ingredients for horseradish sauce.

For the burgers, preheat a large cast-iron griddle or skillet over medium-high heat. Place beef in bowl. Using a handheld grater, grate onion over bowl so meat collects juices. Season with salt, pepper and rosemary. Add garlic, Balsamic and EVOO, mix into meat, and form 4 patties thinner at center and thicker at edges for even cooking. Cook patties 8 minutes, turning occasionally, melt 2 slices cheese on each patty.

Assemble burgers: bun bottom, horseradish sauce, bacon, sliced tomato, burger patty, mushrooms, onions, bun top.