Ultimate Vegan Portobello Mushroom Burgers


Medium  |  Servings: 4  |  Ready In: 45 minutes  |  Yield: 4 Burgers

This is the ULTIMATE vegetarian burger recipe for your summer grilling: Hearty Portobello Mushrooms soak in an oil-free Dijon mustard marinade, with roasted peppers, grilled onions, and a spicy arugula kick. Oil-free, healthy, and satisfying: your plant-based summer dinner is now complete.  Serve with Oil-Free Roasted Rosemary Garlic PotatoesItalian Three Bean Salad, and Grilled Corn and Easter Egg Radish Salad.


  • 4 Bell Peppers, any color
  • 4 Portobello Mushroom Caps
  • 1 sweet onion
  • 2 tablespoons Dijon mustard
  • 1 teaspoon Vegan Worcestershire Sauce
  • 1 teaspoon dried rosemary
  • 1/4 teaspoon salt
  • 1/8 teaspoon black pepper
  • 1 cup baby arugula
  • 4 Seeded Burger Buns

How It’s Done:

Preheat a grill or grill pan over high heat.

To roast the bell peppers: Halve and seed the bell peppers. Place on your grill, cut side up, and grill 8-10 minutes, until well-charred. You can also place under a “High” Broiler for 8-10 minutes to achieve the same effect.

When the peppers are well-blackened, place in an air-tight container. Cover and let steam while you’re preparing everything else, for about 8-10 minutes. After the peppers have steamed, you can easily peel off their charred skin, leaving the roasted pepper flesh.

To marinate the portabello mushrooms: Use a spoon to scoop out the gills of the portabellos. In a medium bowl, combine the mustard, Worcestershire, salt, pepper, and rosemary. Coat each of the mushroom caps completely in the marinade. Let sit for at least 10 minutes, or even overnight.

To grill your onions: Remove the peel of the onion and cut into 1/2-inch thick slices. Place the onions on the hot grill. Let sear about 7 minutes, until well-charred on one side. Flip and continue cooking another 5-7 minutes. When the onions are well-charred, remove from the grill and keep warm.

To grill the mushrooms: Remove the mushroom caps from the marinade. Save the marinade. Place the portobellos on the pre-heated grill, gill-side-up. After 3-4 minutes, flip the portobello caps. Grill another 5-7 minutes, until tender and charred around the edges.

To prepare your burger buns: Halve the buns and scoop out most of the center of the bread, making way for all of your fillings. Toast the buns 3 minutes on a medium hot spot on the grill.

To prepare you arugula: Toss the arugula your reserved marinade.

To assemble the Ultimate Vegan Portobello Mushroom Burgers: When all of your ingredients are ready, assemble your burgers: Toasted bun, roasted pepper, grill onion, mushroom, arugula, another roasted pepper.

Enjoy immediately.

Hearty Portobello Mushrooms pack big flavor and satisfying texture for healthy, plant-based vegan recipes. Use in place of steak in many recipes

Chef Katie’s Tips:

Remove the Gills: Use a spoon to remove the gills of the Portobello mushrooms.  The gills are watery, lacking flavor.  They also give everything a black color, which isn’t as appetizing.

Grill Pan: A cast-iron grill pan works great for indoor grilling year round.  It also makes it easy to char vegetables without worrying about them falling through the cracks.

Multi-Use Marinade: A quick marinade with Balsamic vinegar, Dijon mustard, vegan Worcestershire, and rosemary also works as an oil-free dressing on your finished burger.

Nutrition Facts

Serving size: 1/4 of recipe (1 burger)
Calories 277.74
Calories From Fat (9%) 24.22
% Daily Value

  • Total Fat 2.9g 4%
  • Saturated Fat 0.17g <1%
  • Cholesterol 0mg 0%
  • Sodium 448.85mg 19%
  • Potassium 1156.66mg 33%
  • Total Carbohydrates 54.78g 18%
  • Fiber 11.76g 47%
  • Sugar 13.4g
  • Protein 14.73g 29%
  • Calcium 163.33mg 16%
  • Iron 43.41mg 241%
  • Vitamin A 3856.1IU 77%
  • Vitamin C 0.01mg <1

Shopping and Gear List

  • Organic Wizard’s Sauce, Vegan Worcestershire, 5-Ounce Bottles (Pack of 12)
  • Food For Life Ezekiel 4:9 Sprouted Whole Grain English Muffins, 16 Ounce (Pack of 06)
  • Lodge 10.5 Inch Square Cast Iron Grill Pan. 


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