Portobello Mushroom Burger

Savory grilled portobello mushrooms, onions, spinach, mayo, and sun-dried tomatoes are piled onto a fluffy bun to create a mouthwatering burger experience that happens to be vegetarian. You won’t even miss the meat!

Three mushroom burgers on a platter.
Lori Rice

Hello portobello mushroom burgers!

Why Portobello Mushrooms Are the Best for Burgers

I grew up seeing these as a vegetarian option in restaurants and cafes. But here's the thing, for mushroom lovers (that would be me, you too?), portobellos are perfect for burgers, whether you are vegetarian or not.

The cap of this ginormous cremini mushroom is the perfect size and shape of a burger. The mushroom is meaty and juicy and umami-y.

How To Make Portobello Mushroom Burgers

Paint the caps with a little olive oil, put them on the grill for a few minutes on each side, and you have a perfect grilled mushroom to put between two burger buns.

In the following rendition, we've layered on grilled onions, some sautéed spinach, and sun-dried tomatoes, but it's just as good plain, with a little salt and pepper.

Three mushroom burgers on a platter.
Lori Rice

How To Select the Best Portobello Mushrooms at the Store

Look for mushroom caps that are brown, firm to the touch, and don't have any brown spots. If a portobello is tacky or slimy, do not choose it. For caps that all cook evenly, buy portobellos that are similar in thickness and diameter.

The Best Toppings for Portobello Mushroom Burgers

  • Substitute a garlic and herb cheese spread for the mayonnaise.
  • Substitute aioli for the mayonnaise.
  • Substitute roasted red peppers in oil for the sun-dried tomatoes.
  • Add caramelized onions.
  • Add cheese like feta, mozzarella, or cheddar.

More Vegetarian Burger Recipes to Try!

From the Editors Of Simply Recipes

Portobello Mushroom Burger

Prep Time 10 mins
Cook Time 20 mins
Total Time 30 mins
Servings 4 servings


  • Extra virgin olive oil

  • 8 ounces baby spinach

  • 4 portobello mushroom caps

  • 1 (8-ounce) jar sun-dried tomatoes in oil

  • 1 red onion, sliced into 1/4-inch rounds

  • Kosher salt

  • Mayonnaise

  • 4 hamburger buns


  1. Prepare the grill:

    Heat the grill for high, direct heat.

  2. Wilt the spinach:

    While the grill is heating, if you wish, sauté the baby spinach in a tablespoon of olive oil and a sprinkle of salt in a large sauté pan on medium high heat, just until the spinach wilts, then remove to a plate.

    The gently wilted spinach will stay on the portobello mushroom burger better than raw spinach, which tends to fall off.

    Or, you can use raw baby spinach. Your choice.

    Sauteed greens in a skillet to make a portobello mushroom burger recipe.
    Lori Rice
  3. Clean the mushrooms and brush with oil:

    Wipe the mushrooms clean with a damp paper towel. If you are working with whole mushrooms, slice off the stems. (You can use for another purpose, chopped and sautéed or for making stock.)

    Paint the tops of the mushroom caps with some of the oil from the sun-dried tomatoes.

    Brushing off the top of a portobello mushroom to make a portobello mushroom burger.
    Lori Rice
    Oiling the top of a portobello mushroom to make a portobello mushroom burger.
    Lori Rice
  4. Grill the onion rounds, mushroom caps, and buns:

    Scrape the grill grates clean. Using a folded up paper towel dipped in olive oil, wipe down the grill grates to oil them.

    Brush the onion rounds with some olive oil and place them on the grill.

    Place the mushroom caps on the grill, top side down first. Sprinkle with a little salt. Grill the mushroom caps and the onion rounds for 4-5 minutes per side.

    Grill the burger buns, cut side down, for about 1/2 to 1 minute, until lightly toasted.

    Grilling red onions for a portobello mushroom burger recipe.
    Lori Rice
    Mushrooms on the grill to make a portobello mushroom burger recipe.
    Lori Rice
    Mushrooms on the grill to make a portobello mushroom burger recipe.
    Lori Rice
  5. Assemble:

    To assemble, spread some mayonnaise on each bun. Put a portobello mushroom cap on the bottom, then layer on the spinach, sun-dried tomatoes, and finally some onion. Serve at once.

    Mushroom burgers on a platter with toppings and the top bun spread with mayonaisse.
    Lori Rice
Nutrition Facts (per serving)
442 Calories
24g Fat
49g Carbs
12g Protein
Show Full Nutrition Label Hide Full Nutrition Label
Nutrition Facts
Servings: 4
Amount per serving
Calories 442
% Daily Value*
Total Fat 24g 31%
Saturated Fat 4g 19%
Cholesterol 6mg 2%
Sodium 656mg 29%
Total Carbohydrate 49g 18%
Dietary Fiber 7g 26%
Total Sugars 6g
Protein 12g
Vitamin C 76mg 378%
Calcium 190mg 15%
Iron 5mg 30%
Potassium 1539mg 33%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
Nutrition information is calculated using an ingredient database and should be considered an estimate. In cases where multiple ingredient alternatives are given, the first listed is calculated for nutrition. Garnishes and optional ingredients are not included.