Teriyaki Portobello Mushroom Burgers - 34

Have you marinated beef or pork prior to grilling? Chicken? Seafood too? Most of us have, depending upon the particular cut or desired flavor profile. When did you last marinate a vegetable before hitting the grill? Different story? Me too, so when the opportunity arose to use World Harbors Teriyaki Sauce and Marinade and Meatless Monday arrived I chose Portobello mushrooms as the target veggie. I was craving a burger, that’s usually a given, so the Teriyaki Portobello Mushroom Burgers recipe will try to satisfy my carnivorous craving.

Teriyaki Portobello Mushroom Burgers with a Wasabi Aioli Ingredients:

  • Portobello mushrooms
  • Sliced cheese (I used easy melting Havarti)
  • Burger buns (I used house made Kaiser rolls)
  • 16 oz. bottle of World Harbors Teriyaki Sauce and Marinade
  • Chopped chives plus poppy seeds for garnish
  • ½ cup mayo
  • 1 tsp World Harbors Teriyaki Sauce and Marinade
  • 1 tsp wasabi paste
Teriyaki Portobello Mushroom Burgers - 1
The main ingredients

And I can help out if you want to try out this recipe. Get started with a World Harbors Marinades coupon here

Gently brush and clean the mushrooms and remove the stems:

Teriyaki Portobello Mushroom Burgers - 3
Pop a cap!

Reserve the stems for other gravies or stews, I like to trim them a bit and use them in salads or omelettes.

Place the caps in a deep dish or container and pour the World Harbors Teriyaki Marinade over the tops:

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Pour it on!

Flip the caps over and pour a puddle of the marinade into the portobellos:

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Bottoms Up!

Marinate time? Mushrooms are sponges, the range can be narrow or wide. 30 minutes to a couple hours. For maximum flavor, soak the mushrooms, covered and refrigerated, overnight and they’ll be ready to hit the grill as soon as you arrive home from a busy day.

Set the grill up for two zone or indirect grilling with coals on one side and none on the other. Target temperature is approximately 300 degrees. For added flavor I tossed in a couple small chunks of apple wood:

Teriyaki Portobello Mushroom Burgers - 14
That’s some smokin’ hardwood!

Next time around I’m using oak wood. I love oak smoked beef and portobellos are a beef substitute.

Shake off the excess marinade and place the mushrooms bottom side down on the cool side of the grill to soak up the smoke flavor and yes, these will be reverse-seared Portobello mushrooms:

Teriyaki Portobello Mushroom Burgers - 16
We’re kind of doing it all here: marinating, baking, smoking, reverse-searing, and wait till we get to the aioli!

While the portobello caps smoke on the PK Grill, let’s make up that wasabi aioli. Combine the mayo, World Harbors Teriyaki Sauce and Marinade and the wasabi paste. Combine and keep chilled

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Feel free to up the wasabi if you want to kick up the horseradish heat

Back to the grill which will require close attention from this point forward. After about 30 minutes in the smoke, shift the portobello caps directly over the hot coals to sear. Maintain close vigilance as the mushrooms are rather heat sensitive and the sugars in the marinade can caramelize quickly over direct fire. This is not the time to depart seeking another adult beverage (spoken in the voice of previously humiliating experience). This may not be the time to attempt the eye candy of fancy crosshatch grill marks. In other words, if left too long on the grill, the mushrooms can burn really quick, so keep checking with the tongs:

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The liquid in the middle is actually boiling. Check the bubbles

Here’s a pic illustrating “the sear becoming the char”.

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There will be some blackening but don’t sweat it. It won’t taste burnt at all. These didn’t

Now the $64,000 dollar question, when are they done? Rare? Medium or well done? No instant read thermometer needed, just check two things. When the center where the stem vacated becomes pliable or soft they’re done.

Move the portobello caps to the cooler side of the grill grates and top with a good melty (is that a word?) sliced cheese. I used thin sliced Havarti:

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Looking good here but pay attention with a hot grill and soft cheeses. A significant amount of cheese ended up on the bottom of the grill:

Teriyaki Portobello Mushroom Burgers - 28
Another option would be to drain the juice out of the cap, and then place them cap side down and place the cheese in what is essentially a portobello bowl at this point

Next step, toast your buns! I lined up house made kaiser rolls on a cookie sheet and hit the insides with a quick spritz of cooking spray. It beats the heck out of buttering each bun and works great when grilling for a crowd. Place the buns sprayed side down over hot coals ever so briefly, just enough to achieve a light toasting then paint the buns with the teriyaki wasabi aioli , dust the now teriyaki portobello burgers with chopped chives or scallions, and sprinkle with poppy seeds:

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Plated and ready to eat

Would I do this again? I’ve already purchased the next batch of portobello mushrooms. Was it good? Nope, it was great and a very enjoyable meat substitute. The sweetness of the World Harbors Teriyaki Marinade balanced the punch of the wasabi in the aioli and the texture was meaty and satisfying. Takeaways? I’ve added this to my list of Meatless Monday recipes. Actually, I don’t observe Meatless Monday so it will be for any day I choose to be meatless. Soak your portobello caps in World Harbors Teriyaki Sauce and Marinade, smoke and reverse sear the mushrooms, toast your buns, paint ‘em with the teriyaki wasabi aioli and enjoy a Meatless Monday on whatever day it is.

***Editor’s Note ~ We at GrillinFools.com prefer Meaty Monday to Meatless Monday, and are not quick to adopt a plant based or vegetarian diet, but I’ve got to say, those portobello burgers were out of this world good***

If you have any questions, feel free to leave them below or send me an email.

Full disclosure, World Harbors partnered GrillinFools on this recipe

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Teriyaki Portobello Mushroom Burgers with Wasabi Aioli

Portobello mushroom caps, marinated in World Harbors teriyaki sauce and marinade, grilled and slapped on a toasted bun with some harvarti cheese and a wasabi aioli
Prep Time5 mins
Cook Time35 mins
Total Time40 mins
Course: Entree
Cuisine: vegetarian


  • portobello mushroom
  • sliced cheese (I used easy melting Havarti)
  • burger bun (I used house made Kaiser rolls)
  • 16 oz World Harbors Teriyaki Sauce and Marinade
  • chives chopped (for garnish)
  • poppy seeds (for garnish)
  • ½ cup mayonnaise
  • 1 tsp World Harbors Teriyaki Sauce and Marinade
  • 1 tsp wasabi paste


  • Remove the stems from the portobello caps
  • Place caps in a high sided dish or plastic bag, pour teriyaki marinade over the caps to coat
  • Place in the fridge for 30 minutes to 24 hours
  • Prepare the grill for two zone grilling with coals on one side and none on the other
  • Target temp for the grill is 300 degrees
  • Throw a chunk of apple wood on the coals and place the mushroom caps on the side with no coals and close the lid
  • Smoke for the mushrooms for about 30 minutes
  • While the portobellos are smoking, combine the mayo, wasabi and teriyaki to make the aioli
  • After 30 minutes, sear the mushroom caps on over the coals about 2 minutes per side
  • Pull the portobellos off the heat and place cheese on top
  • Once the cheese has melted, spray the insides of the buns with oil and toast over the hot coals
  • Spread the aioli over the buns and top with the portobello caps and sprinkle with chives and poppy seeds
  • Serve




Greg Thomas

Greg Thomas

Greg Thomas

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