Sep 07 2026
RestaurantsCarl's Jr.Portobello Mushroom Big Angus Burger® Recipe

Portobello Mushroom Big Angus Burger® Recipe

Inspired by Carl's Jr.
Time45m
Serves4

Make Portobello Mushroom Big Angus Burger® Recipe in just 45m. Get the full recipe with step-by-step instructions at pekinthechef.com.

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Ingredients

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Burger Patties & Marinade

Optional Burger Sauce

Method

Burger Patties & Marinade

  1. 1

    Prepare mushrooms

    Wipe Portobello caps clean with a damp paper towel. Remove stems and, if desired, use a spoon to scrape the gills from the underside to reduce moisture and bitterness. Pat dry.

  2. 2

    Make marinade

    In a shallow dish or bowl, whisk together 4 tbs olive oil, 2 tbs balsamic vinegar, 1 tbs soy sauce, 1 tsp Worcestershire sauce, 2 tsp minced garlic, 1 tbs chopped thyme, 1 tsp smoked paprika, 1 tsp kosher salt and 1 tsp freshly ground black pepper until combined.

  3. 3

    Marinate mushrooms

    Place the mushroom caps in the dish, smooth side up, then turn to coat both sides thoroughly in the marinade. Reserve about 1 tbs of marinade for basting. Cover and refrigerate for at least 20 minutes and up to 2 hours. Bring to near room temperature 10 minutes before grilling.

Burgers & Build

  1. 4

    Preheat grill

    Preheat a gas or charcoal grill to medium-high (about 400°F / 200°C). If using a skillet or grill pan, heat it over medium-high heat and brush lightly with oil.

  2. 5

    Toast onions (optional)

    If you prefer softened grilled onions, toss thinly sliced red onion with 1 tsp olive oil and a pinch of salt, and grill or pan-sear for 4–6 minutes until lightly charred and softened. Set aside.

  3. 6

    Grill mushrooms

    Place marinated Portobello caps gill-side down on the preheated grill. Cook for 4–5 minutes, then flip, brush with the reserved marinade, and grill another 3–4 minutes. Total cook time should yield tender, slightly charred mushrooms. During the last 1–2 minutes of cooking, place a slice of cheddar on each mushroom cap and close the grill lid or cover the skillet so the cheese melts.

  4. 7

    Toast buns

    While mushrooms finish, butter the cut sides of the buns. Place them cut-side down on the grill or pan for 1–2 minutes until golden and crisp. Remove and keep warm.

  5. 8

    Assemble burgers

    Spread approximately 2 tbs burger sauce (or your chosen condiment) on the bottom halves of the toasted buns. Layer 1 leaf of lettuce, a slice of tomato, the melted-cheddar-topped Portobello cap (cheese side up), 2 pickle slices, and grilled red onion as desired. Spread additional sauce on the top bun and place over the stack. Serve immediately.

Optional Burger Sauce

  1. 9

    Make sauce

    In a small bowl, whisk together 4 tbs mayonnaise, 1 tbs ketchup, 1 tsp Dijon mustard, 1 tsp sweet pickle relish, 1 tsp hot sauce (optional) and 1 tsp paprika until smooth. Taste and adjust seasoning, adding a pinch of salt if needed. Use about 2 tbs per burger; refrigerate any leftover sauce up to 5 days.

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