Mushroom Steak

Ingredients

• 4 largeportobello mushrooms
• 3 tablespoonsno-sugar-added balsamic vinegar (or regular balsamic vinegar)
• 3 tablespoonsketo soy sauce (or regular or gluten-free soy sauce)
• 2 tablespoonsextra-virgin olive oil (or vegetable oil)
• 1 tablespoon, optionalWorcestershire sauce (choose a vegan version for a vegan dish)
• 1 teaspoonsmoked paprika
• 3/4 teaspoongarlic powder
• to tastesalt and freshly cracked black pepper

Instructions

1. 1

   Clean mushrooms

   Gently wipe away any dirt with a damp paper towel or soft brush; do not wash the mushrooms. Cut off the stems, then scoop out the brown gills with a spoon.

2. 2

   Mix marinade

   In a large, shallow baking dish, whisk together the balsamic vinegar, soy sauce, olive oil, Worcestershire sauce, smoked paprika, garlic powder, salt and pepper. Taste and adjust the seasoning if you like, keeping in mind that the flavours will taste more concentrated in the marinade.

3. 3

   Marinate mushrooms

   Put the mushrooms in the dish and brush the marinade over all sides. Leave them for 10–20 minutes, turning and brushing them again halfway through.

4. 4

   Sear first side

   Heat a large grill pan or cast-iron frying pan over medium-high heat until very hot. Brush the base with oil, add the mushrooms and press them down gently with a spatula. Sear without moving them for 4–5 minutes.

5. 5

   Sear second side

   Turn the mushrooms over and cook the other side for about 4–5 minutes, until browned and tender. Add a little more oil if needed, or brush on extra marinade. Avoid overcrowding the pan so the mushrooms sear rather than steam. Serve in keto buns or with steamed or grilled vegetables.

6. 6

   Grill outdoors

   For an electric grill, preheat it to medium-high, 177–204°C (350–400°F). Clean the grill and oil the grates. Lift the mushrooms out of the marinade and place them cap-side down on the hot grill. Cover and cook for 4–6 minutes, then turn them over and grill, covered, for another 3–5 minutes.

What is mushroom steak?

Mushroom steak is a plant-based main made by seasoning and cooking large mushroom caps until they are browned and tender. Portobellos are especially suited to the job because their broad caps are easy to grill and serve whole.

This American-style version uses a savoury balsamic and soy marinade, with smoked paprika for a smoky note. A brief marinade and a hot cooking surface give the caps flavour and colour without a long cooking time.

Nutrition and macros by portion

The nutrition label shows one serving as written: 97 calories, 3g protein, 6g carbs, 7g fat.

The mushrooms contribute some carbohydrate and protein, while the olive oil carries most of the fat; the soy sauce and Worcestershire sauce also contribute to the savoury flavour. Pair a serving with steamed or grilled vegetables, or add a bun if you want a more substantial plate.

Choosing and preparing portobellos

Portobello caps: Choose large, firm mushrooms that will hold together as they cook. Wipe away dirt rather than rinsing them, as the method calls for dry cleaning.

Gills and stems: Removing the stems and spooning out the gills leaves a smoother cavity for the marinade. Work gently so the cap does not break.

A balanced marinade

Savoury base: Soy sauce and Worcestershire sauce bring depth, while balsamic vinegar adds tang. Use a vegan Worcestershire sauce if keeping the dish vegan.

Spices: Smoked paprika and garlic powder season the caps without adding fresh garlic, which can scorch on a hot pan. Taste the marinade before adding it, but remember its flavours are concentrated.

Getting a good sear

Hot pan: Let the grill pan or cast-iron pan heat thoroughly before adding the mushrooms. A properly hot surface helps the caps brown instead of releasing moisture and steaming.

Room to cook: Arrange the mushrooms without crowding them and leave them undisturbed for 4–5 minutes on the first side. Turn them once the underside is browned, then cook the other side until tender.

How to judge doneness

Colour: Look for browned patches on both sides rather than relying on a fixed colour across the entire cap. If the mushrooms are sticking, give them a little longer before turning.

Texture: The caps should feel tender when pressed gently with a spatula, but still hold their shape. The stated cooking time is about 4–5 minutes per side in a pan.

Indoor pan or outdoor grill

Grill pan: Use medium-high heat and oil the pan before adding the marinated caps. Keep the mushrooms in a single layer so they can sear.

Electric grill: Preheat to 177–204°C and oil the clean grates. Grill the caps covered, cap-side down for 4–6 minutes, then turn and cook covered for another 3–5 minutes.

Serving ideas

For a bun: Tuck a cooked cap into a bun and add your preferred toppings. Keto buns are one suggested option, but regular buns also work.

For a lighter plate: Pair the mushrooms with steamed or grilled vegetables. Serve any extra sauce alongside rather than adding it all at once.

Recipe notes & tips

• Wipe the mushrooms clean with a damp paper towel or soft brush rather than washing them.
• Brush marinade over both sides and turn the caps halfway through the marinating time.
• Heat the pan fully before adding the mushrooms so they can brown.
• Cook in batches if needed to leave space between the caps.
• Use vegan Worcestershire sauce if you want the dish to remain vegan.

Variations

• Use vegetable oil: Swap it for the olive oil if preferred.
• Choose regular soy sauce: Use regular soy sauce in place of the keto option.
• Make it gluten-free: Choose a gluten-free soy sauce.
• Skip Worcestershire: Leave it out for a simpler marinade.
• Serve with buns: Put the cooked caps in keto or regular buns.
• Use the electric grill: Cook the caps covered using the alternative grill method.

Common mistakes to avoid

• Washing the mushrooms: They can take on water; wipe away dirt with a damp towel or soft brush instead.
• Crowding the pan: The caps may steam instead of searing; cook them in batches.
• Turning too soon: The first side needs 4–5 minutes undisturbed to brown; let it sear before flipping.
• Using fresh minced garlic: It can burn over high heat; use the specified garlic powder.
• Adding all the marinade without tasting: Its flavours are concentrated; taste it first and adjust the seasoning carefully.

How to store

Refrigerate leftover cooked mushrooms in an airtight container and use within 3–4 days. Reheat in a frying pan over medium heat until warmed through; avoid prolonged cooking, which can make them soft.

Frequently asked questions