Marinated Portobello Mushroom Burgers

May 01, 2019

It’s almost grilling season!! I kind of want to make weekend grilling a thing at my house this year, so I’m testing some recipes. I already have some fun burger recipes on the site, so I figured it was time to make an option for all of my vegetarian friends. Marinated Portobello Mushroom Burgers are probably the easiest and tastiest vegetarian burger option, ever. And guess what? If you’re a meat eater, these marinated and grilled portobello mushrooms make a great topper to a regular burger, too!

Marinated Portobello Mushroom Burgers

Tips for Buying Portobello Mushrooms

When buying portobello mushrooms, pay really close attention to the way they are priced. You’ll usually see them sold one or two ways: loose and priced per pound, or packaged in sets of two or three for a set price. Even though they are the exact same product, you might find a drastic price difference between the two options.

The loose mushrooms at my store today were $5.99 per pound. The packs or two mushrooms were sold for a set price of $3.99, but the package listed an approximate weight of 8oz., or 1/2 pound. So, if I had bought the packaged mushrooms I would have paid $2 more per pound. 🤯 I picked up two of the loose portobello caps and went on my way! :)

Do I Have to Grill These Marinated Portobello Mushroom Burgers?

While testing this recipe I also tested cooking them in a skillet and it worked quite well, although you won’t get those pretty grill marks. When cooking in a skillet, simply cook over medium heat, flipping the mushrooms occasionally, until they release all of their moisture and the liquid in the skillet has evaporated.

In addition to cooking these marinated portobello mushroom burgers on an outdoor grill, you can also use a grill pan, like in the step by step photos below. The cast iron grill pan I used fits right over the gas burners on the stove and has ridges on one side and a flat griddle on the other side. Here is a similar item on Amazon: Lodge Grill/Griddle Pan (affiliate link). A less expensive option would be a grill pan skillet, like this Lodge 10.5″ Square Grill Pan (affiliate link).

Marinated Portobello Mushroom Burgers

With their deep savory flavor, Marinated Portobello Mushroom Burgers are a fast and easy vegetarian option for summer grilling.

2 Tbsp olive oil ($0.08)
2 Tbsp soy sauce ($0.12)
1 Tbsp apple cider vinegar ($0.03)
1 tsp brown sugar ($0.02)
1/4 tsp oregano ($0.02)
1/4 tsp garlic powder ($0.02)
1/4 tsp onion powder ($0.02)
1 tsp smoked paprika ($0.10)
freshly cracked pepper ($0.03)
2 portobello mushroom caps (about 1/2 lb. total) ($2.94)
2 buns ($0.83)

Optional Toppings

1 cup spring mix ($0.32)
1 tomato ($0.70)
1/4 red onion, sliced into rings ($0.07)
4 Tbsp mayonnaise ($0.40)

In a small bowl, stir together the olive oil, soy sauce, apple cider vinegar, brown sugar, oregano, garlic powder, onion powder, smoked paprika, and a little freshly cracked pepper (about 10 cranks of a pepper mill).
Remove the stems from the portobello mushrooms.* Place the mushrooms in a shallow dish, gill sides up. Pour some of the marinade into the gills, then flip the mushrooms and pour the rest over the top. Let the mushrooms marinate for 30 minutes, flipping occasionally.
Heat a grill or grill pan over medium to medium-high heat. Once hot, add the marinated portobello mushrooms and cook for about 7 minutes on each side, or until the mushrooms are soft and have released most of their liquid.
Build your marinated portobello mushroom burgers on a bun with your preferred toppings. I love the classic mix of mayonnaise, sliced tomato, onion rings, and lettuce or spring mix.

*You can save the mushroom stems use them later in an omelette (chopped), or save with the rest of your vegetable scraps in the freezer for making vegetable stock later.

While you’ve got the grill going, grill up some vegetables for Grilled Vegetable Pasta Salad to serve on the side!

Step by Step Photos

To make the marinade for the portobello mushroom burgers, combine 2 Tbsp olive oil, 2 Tbsp soy sauce, 1 Tbsp apple cider vinegar, 1 tsp brown sugar, 1/4 tsp oregano, 1/4 tsp garlic powder, 1/4 tsp onion powder, 1 tsp smoked paprika, and some freshly cracked pepper (maybe 10 cranks of a pepper mill) in a bowl.

If the mushrooms have long stems, pull the stems off. Place the portobello mushrooms in a shallow dish, gill side up, and pour some of the marinade into the gills. Flip the mushrooms over and pour the rest of the marinade over top.

Marinate the mushrooms for 30 minutes, flipping them a few times throughout.

Heat an outdoor grill, grill pan, or skillet over medium. Once very hot, add the marinated portobello mushrooms and cook on each side for about 7 minutes, or until the mushrooms are very soft and have released most of their moisture.