Vegan Portobello Mushroom Burger

A burger with ketchup, lettuce, yellow cheese sauce, bell peppers, guacamole and grilled mushroom cap on brown paper. French fries are placed next to it.

Vegan Portobello Mushroom Burger

This vegan portobello mushroom burger is piquant and scrumptious at the same time. Grilled portobello mushroom caps are seasoned with a fajita spice mix, then layered among guacamole, salsa, vegan nacho cheese sauce, and spicy fajita veggies.

Course Main Course

Cuisine American, Tex-Mex

Keyword fajitas burger, portobello mushroom burger, vegan mushroom burger, vegan portobello recipe

Prep Time 15

Cook Time 20

Marinating time 2

Total Time 35

Servings burgers

Calories 362kcal

Author Nandor Barta

Equipment

Ingredients

Portobello mushroom marinade

5 Tbsp Olive oil
1 clove Garlic
1 Tbsp Lime juice or lemon juice
¼ tsp Sweet smoked paprika powder
½ tsp Fajitas spice mix or see below for homemade spice mix
¼ tsp Salt
¼ tsp Ground black pepper

Homemade fajita spice mix

½ tsp Hot chili powder or flakes
1 Tbsp Sweet smoked paprika powder
1 + ½ tsp Ground cumin seeds
1 + ½ tsp Garlic powder
1 + ½ tsp Oregano

To assemble the burger

2 Large portobello mushrooms
2-4 leaves Lettuce
½ serving Fajita veggies (½ bell pepper and ¼ onion)
6 Tbsp Salsa
6 Tbsp Nacho cheese sauce
6 Tbsp Guacamole

US Customary - Metric

Instructions

Make the fajita marinade

Take a small-sized bowl. Add olive oil, salt, black pepper, fresh garlic cloves, freshly squeezed lime juice, and fajitas spice mix. Stir until combined.

Soak mushrooms in marinade (min. 2 hours, but overnight is preferred)

Peel the portobello mushrooms. Take out the stems.
Place the mushroom caps in a shallow bowl and pour the marinade on top of them.
Toss and turn a couple of times, to make sure they are covered everywhere.
Repeat this step after an hour (in case of short marinate) or in the morning (in case of overnight marinate) to make sure mushrooms are not getting dry.

Pan-frying

Heat the grill pan to medium. Once sizzling hot, place the marinated mushroom caps on it.
Cook both sides for approx. 5 minutes. You can push the mushrooms down for a few seconds each side with a grill spatula to allow the greater surface of the mushrooms to be grilled.
Brush each side with the leftover marinade once.
Cover the grill pan to allow hot air to circulate through the pan (just as it would in a real gas grill).

Assemble

Take the bottom part of a hamburger bun (if you toasted it a bit - even better)
Spoon some salsa sauce on the first part of the burger.
Add a couple of green leaf lettuce leaves.
Spoon some vegan nacho cheese sauce.
Add fajitas bell pepper and onion slices. (We have a detailed guide on how to make fajita veggies the EASIEST WAY).
Add the grilled portobello mushroom caps.
Finish it off with some guacamole.

Video

Notes

How to bake them in the oven?

You can use a glass oven-safe dish or a grill pan (provided that the handle is not made of plastic). Preheat the oven to 400 Fahrenheit (ca. 204 °C) and grill them under the broiler for 10 minutes, turning them at halftime.

How to grill them on a gas grill without burning?

Our little trick is to use aluminum foil drip pans. Similar to the oven grilling, preheat your gas grill to 400 Fahrenheit (ca. 204 °C) and grill the marinated mushroom caps for 10 minutes, turning them at halftime.

Nutrition