Vegan Pesto Portobello Burgers

Vegan Pesto Portobello Burger

Prep Time: 20 min Cook Time: 15 min Total Time: 35 min Servings:

Portobello burgers will always hold a special place in our hearts here at This and That Kitchen, largely because they were one of the very first plant-based meals that we learned to cook in our tiny college apartment! Back then, we would stuff the center with vegan cheese and garlic powder and pop them in the oven. And don't get us wrong, those burgers were delicious, but we knew that there was so much potential to make them a powerhouse of flavor! One thing we learned from making one of our all-time favorite pizzas was that portobello mushrooms paired with pesto is a match made in flavor heaven. To balance the richness of the pesto and portobello, we added a vegan garlic aioli made with fresh lemon juice and some fresh, crisp arugula. When you bring everything together, you have an indulgent, elevated burger that you can pull together in just over 30 minutes! Your friends and family will be blown away by this burger!



For Burger:

  • 4 large portobello mushroom caps, washed and stems removed
  • 1 batch of our Vegan Pesto 
  • 1 large Vidalia onion, sliced

For Garlic Aioli:

  • 1/2 cup of vegan mayonnaise (We use Trader Joe's Vegan Mayo!)
  • 4 tsp fresh lemon juice
  • 1 tsp garlic powder
  • 2 cloves of garlic, minced
  • Salt and fresh-cracked black pepper to taste

For Serving:

  • 3 cups of baby arugula
  • 4 hamburger buns, toasted in a skillet


  1. Prepare pesto according to the recipe and set aside covered in the refrigerator.

  2. If you are grilling your mushroom caps, heat up the grill, and allow the garlic cloves to grill for 2-3 minutes on high. Remove from grill and mince. If not using the grill, then simply mince the raw garlic. Tip: To make your life easier, consider using a garlic press!

  3. Mix together the mayonnaise, lemon juice, garlic powder, minced garlic, salt, and pepper. Taste and adjust seasonings as needed. Tip: To make your life easier, consider using a citrus press!

  4. After cleaning the mushroom caps, pat with a paper towel to absorb as much moisture as possible. Place the caps upside down with the gills facing up, and scoop 1/4 cup of pesto into each of the caps. Use a spatula or spoon to evenly spread the pesto across the caps.

  5. Place the mushroom caps onto the top rack of your grill over medium heat. Grill for 10-15 minutes, or until the mushrooms are cooked throughout and begin to release a lot of liquid. Tip: If you don't have a grill, these alsoturn out really well in the oven (set to 375° F or 190° C).

  6. While the mushrooms are cooking, add the onion slices to a skillet with 1 tbsp of olive oil. Sauté the onions until they are caramelized and translucent. Remove from heat and set aside.

  7. Remove mushrooms from the grill (or oven) and allow as much excess liquid to drain off as possible. 

  8. Assemble the burgers by spreading a little of the leftover pesto across the bottom bun and the garlic aioli across the top bun, placing the mushroom caps on the bottom bun,  and adding caramelized onions and arugula before topping the burger off with the top bun. 

  9. Enjoy!


Made it? We would love to hear how it went! Upload a picture and tag us!