King Oyster Mushroom Steaks (Vegan + Gluten-Free)

These grilled king oyster mushroom steaks are the perfect vegan addition to any barbecue. Delicious and gluten-free, they're also great when pan-fried.

Meaty king oyster mushrooms are the perfect vessel for the garlic, ginger, soy sauce, and sesame oil in this marinade. They turn crispy and golden on the outside, while the flesh on the inside remains soft and tender.

Don't worry if you don't have king oyster mushrooms – you can use the marinade for other mushrooms such as portobellos, or veg such as sliced aubergine.

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What are king oyster mushrooms?

The king oyster mushroom, or pleurotus eryngii, is a large edible mushroom and the largest species in the oyster mushroom family. Featuring a thick white stem and small, slightly brown cap, it is prized for its meaty texture.

In recent years, king oyster mushrooms have surged in popularity as a meat replacement in vegan and vegetarian cooking. They can also be used to mimic the texture of scallops, as seen in this recipe for the ultimate vegan fish pie.

What do king oyster mushrooms taste like?

King oyster mushrooms have a very mild umami taste, making them the perfect vessel for strong flavours such as the garlic, ginger, and soy sauce in this recipe.

Some say that king oysters have a subtle woody and seafood-like taste, which may explain the English name of 'oyster' mushrooms. I've never really noticed a seafood taste myself, and you certainly shouldn't let that put you off trying them.

Where do king oyster mushrooms grow?

King oyster mushrooms are native to the Mediterranean, Middle East, and North Africa, but the largest producers these days are the East Asian countries of China, South Korea, and Japan.

It's also becoming increasingly popular to grow these mushrooms (and others) at home.

Where to buy king oyster mushrooms?

Here in the UK, I tend to buy king oyster mushrooms from a local international supermarket. I've also noticed them starting to appear on the shelves in larger supermarket stores.

If you're not sure where to find them, I'd start by asking in a local wholefoods/organic/international store or by doing a little research online.

Are king oyster mushrooms healthy?

Edible mushrooms are virtually fat-free, low in calories, and contain varying degrees of protein and fibre. They also contain B vitamins as well as a powerful antioxidant called selenium.

Most of the fat in this recipe comes from the sesame oil in the marinade. You can cut this out if you like, but it adds delicious flavour and helps prevent the mushrooms from sticking to the grill.

How to marinate king oyster mushrooms

Marinating the mushrooms before cooking is a great way to permeate them with the aromatic flavours. It also removes some of the moisture, giving them a meatier texture.

In a large freezer bag or bowl, mix together all of the ingredients apart from the mushrooms. The great thing about a freezer bag is that you can use your hands to combine everything without any mess.

Cut each mushroom lengthways into three slices, then add these to the marinade bag/bowl. Take a couple of minutes to coat the mushrooms evenly in the marinade, then leave for approx. 15 minutes on the work surface or in the fridge.

Again, a freezer bag makes it easy to move everything around and you can use the zip seal to help trap the flavour. If using a bag, remember to wash it out and reuse in future!

Barbecuing / grilling the king oyster mushroom steaks

Preheat the barbecue/grill to a medium heat (not scorching hot or else the mushrooms will quickly burn and/or dry out).

Add the mushroom slices and cook for approx. 5 minutes on each side, doing this in batches if necessary. The mushrooms should be golden on both sides with slightly crispy edges and char marks.

Pan-frying the king oyster mushroom steaks

To pan-fry these mushrooms you'll probably have to cook in batches. Heat a small amount of cooking oil in a pan on medium heat and add the mushroom slices, avoiding any overlaps.

Cook for 3-4 minutes on either side, or until both sides are golden with slightly crispy edges. Transfer to a plate and repeat with the remaining mushrooms.

Can I use this marinade for other mushrooms?

This marinade works well with lots of other ingredients. If you can't get your hands on king oyster mushrooms then portobello mushrooms are a great substitute.

You can also use the marinade for vegetables such as sliced aubergines, which will really absorb all the flavours.

Serving suggestions for king oyster mushroom steaks

Enjoy these mushrooms as part of a larger barbecue meal, either as a main or side. I like to garnish them with sesame seeds and fresh herbs such as coriander or parsley.

Other serving suggestions include:

• Mediterranean couscous salad
• Moroccan couscous with roasted veg
• Three-bean salad with lemon, mint and parsley
• Crispy baked potato wedges
• Vegan scalloped potatoes (dauphinoise)
• Roasted cauliflower
• Pico de gallo

Tips/variations for king oyster mushroom steaks

• Leftover marinade: If you have leftover marinade, don't throw that stuff away! Use it in a stir-fry, soup, or stew, or recycle it with more soy sauce and sesame oil to then marinate something else.
• Quantity: Four whole mushrooms is a nice amount for two main servings, or can provide many more servings as a side.
• Marinating time: I find that anywhere from 15-30 minutes is a good window for marinating mushrooms.
• Cooking time: This will vary slightly depending on the type of barbecue/grill and the cooking temperature.
• Reuse your freezer bag: If using a freezer bag for the marinade, remember to wash it out and reuse in future.
• Garlic & ginger: You want the garlic and ginger to be very finely chopped or minced, almost to a paste. On that note, you could also use shop-bought pastes.
• Heat: I like to include the chilli seeds, but you can remove these if you don't like the heat. 
• Salt/pepper/seasoning: I find that the salty tamari/soy sauce and other aromatics provide tonnes of flavour, but feel free to add any additional seasonings you like.
• Gluten-free: Tamari is a variant of soy sauce that’s usually gluten-free. If this recipe needs to be 100% gluten-free, make sure you use a GF soy sauce or tamari.

How to store cooked king oyster mushrooms

Refrigerate: You can store the cooked mushrooms in the fridge for up to a week. For the best results, store in a resealable bag or container.

Freeze: I'd avoid doing this, as freezing can affect the texture and the defrosting process will draw out a lot of the moisture (in this case, all that delicious marinade). If you really want to freeze the cooked mushrooms, store in a resealable bag or container and freeze for up to six months.

More vegan recipe ideas

If you liked this recipe, you may also enjoy:

• Grilled Teriyaki Tofu Steaks
• Ultimate Vegan Fish Pie
• Teriyaki Grilled Aubergine
• Mediterranean Couscous Salad
• Rainbow Slaw with Sesame Ginger Dressing
• Courgette and Carrot Salad with Peanut Dressing
• 5-Minute Peanut Noodles
• Vegan Rice Paper Rolls

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