Dinner

Best Portobello Mushroom Burger Recipe

ByHailey Reed February 11, 2026February 11, 2026

Introduction

If you’re looking for a delicious and satisfying vegetarian burger, this Best Portobello Mushroom Burger recipe is a perfect choice. Juicy grilled portobello mushrooms topped with creamy Brie and flavorful pesto mayo make for a mouthwatering meal that even meat lovers will enjoy.

A close-up of a cheeseburger on a white plate sitting on a white marbled surface, showing three main layers inside a soft bun: the bottom layer is a juicy cooked beef patty covered in melted white cheese, the middle layer is bright green leafy lettuce, and the top layer is a thick red tomato slice. The bun is golden brown and slightly shiny on top. The melted cheese drips slightly over the beef patty edges, and the lettuce leaves curl gently around the tomato. The photo is clear and focused on the sandwich details, with soft light highlighting the fresh ingredients. photo taken with an iphone --ar 4:5 --v 7

Ingredients

4 portobello mushroom caps
¼ cup olive oil
2 Tbsp. lemon juice
1 garlic clove, minced
¼ tsp. salt
¼ tsp. pepper
3 Tbsp. mayonnaise
1 Tbsp. pesto, store-bought or homemade
4 oz. Brie cheese
4 hamburger buns

Instructions

Step 1: Trim the stems off the portobello mushrooms and gently wipe away any dirt using a wet paper towel.
Step 2: In a bowl, combine olive oil, lemon juice, minced garlic, salt, and pepper. Place the mushrooms gill-side down on a plate and brush lightly with the olive oil mixture. Flip and brush the gill side with the remaining mixture. Allow to marinate for 10 minutes.
Step 3: Preheat your grill to medium heat. Place the mushrooms gill side up on the grill and cook for about 4 minutes until you see nice grill marks. Turn the mushrooms 90° to create crosshatch marks and cook for another 2 minutes. Flip the mushrooms and repeat the grilling and turning process. Finally, flip the mushrooms once more and place 1 ounce of Brie on each, allowing it to melt slightly. Remove from the grill and set on a plate.
Step 4: In a small bowl, mix the mayonnaise and pesto together. Spread about 1 tablespoon of this mixture on the inside of each hamburger bun. Assemble the burgers by placing a grilled mushroom on each bun, then add your favorite toppings before serving.

Tips & Variations

For extra flavor, marinate mushrooms for up to 30 minutes before grilling.
Swap Brie cheese for goat cheese or mozzarella for a different creamy texture.
Add caramelized onions or roasted red peppers as additional toppings.
If you don’t have a grill, mushrooms can be cooked on a grill pan or broiled in the oven.

Storage

Store any leftover grilled mushrooms and pesto mayo separately in airtight containers in the refrigerator for up to 2 days. Reheat mushrooms gently in a skillet or microwave before assembling your burger. Buns are best stored separately to avoid sogginess.

How to Serve

A close-up image of a sandwich on a white plate, featuring a soft bun split into two layers. The bottom bun holds a juicy, cooked patty covered with melted white cheese that drips slightly down the side. Above the cheese is a layer of crisp green lettuce, topped with two bright red tomato slices. The top bun is golden brown with a slightly shiny finish. The sandwich rests on a white marbled surface. Photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I use other types of mushrooms for this recipe?

While portobello mushrooms work best because of their size and meaty texture, you can substitute with large cremini mushrooms, but the flavor and cooking time may vary.

How do I prevent the mushrooms from getting soggy?

Make sure to not over-marinate and grill the mushrooms over medium heat to retain their structure. Also, avoid placing wet toppings directly on the bun to keep it from becoming soggy.