Aug 26 2026
RestaurantsRoni's Pub + KitchenMushroom Onion Bacon Swiss Recipe

Mushroom Onion Bacon Swiss Recipe

Time25m
Serves1

Swiss, grilled shrooms and onions, and crispy bacon

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Ingredients

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Sandwich

Bacon

Optional garnish

Method

Bacon

  1. 1

    Cook bacon until crisp

    Place a medium skillet over medium heat. Add 3 slices of bacon in a single layer and cook 3–4 minutes per side, flipping occasionally, until crisp and browned. Transfer bacon to a paper-towel–lined plate to drain and keep warm. Reserve 1 teaspoon bacon fat in the skillet and discard the rest or save for another use.

Mushrooms & Onions

  1. 2

    Slice and prep

    Clean mushrooms with a damp towel and slice thinly (about 1/4 inch). Thinly slice the half onion into half-moons. Mince garlic and measure thyme and seasonings.

  2. 3

    Sauté vegetables

    Return the skillet with reserved bacon fat to medium-high heat. Add 1 tablespoon olive oil and 1 teaspoon butter. When butter melts and oil shimmers, add the sliced mushrooms in a single layer; let them sear undisturbed 2 minutes to brown, then stir. Add the sliced onions and continue to cook 4–5 minutes, stirring occasionally, until mushrooms are golden and onions are soft and caramelized at the edges. Add the minced garlic and 1/2 teaspoon thyme in the last 30–45 seconds, stirring until fragrant. Season with 1/2 teaspoon salt and 1/4 teaspoon black pepper. Taste and adjust seasoning if needed.

Assemble & Grill

  1. 4

    Butter bread and layer

    Spread butter evenly on the outsides of both sourdough slices. On the unbuttered side of one slice, place 1 slice Swiss cheese, top with the warm mushroom-onion mixture (about half the batch if making for more servings), break the 3 bacon slices in half and arrange over the veggies, then top with the second slice of Swiss cheese and the other slice of bread, buttered side out.

  2. 5

    Grill the sandwich

    Heat a clean skillet or griddle over medium-low to medium heat. Place the assembled sandwich in the skillet and cook 3–4 minutes per side, pressing gently with a spatula, until bread is golden-brown and cheese is melted. If the bread browns before the cheese melts, lower the heat and cover the skillet for 1–2 minutes to help cheese melt through.

  3. 6

    Rest and serve

    Transfer sandwich to a cutting board, let rest 1 minute, slice in half, sprinkle chopped parsley if using, and serve immediately.

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