Sometimes you want the satisfaction of a burger without the beef—and these Mushroom and Spinach Stuffed Portobello Burgers deliver that and more. Earthy portobello caps become hearty “buns” for a savory filling of garlic-sautéed mushrooms, tender spinach, and melted cheese. This recipe is as perfect for Meatless Monday as it is for impressing guests at an al fresco barbecue.

Ingredients

• 4 large portobello mushroom caps, stems removed

• 2 tablespoons balsamic vinegar

• 2 tablespoons olive oil, divided

• Salt and pepper

• 1 small yellow onion, finely chopped

• 8 oz cremini or baby bella mushrooms, sliced

• 3 cups fresh spinach

• 2 cloves garlic, minced

• ½ cup shredded mozzarella or Gruyère cheese

• 4 whole-grain burger buns

• Toppings: sliced tomato, lettuce, red onion, sliced avocado

Preparation Steps

1. Marinate the mushrooms.

   • In a shallow dish, whisk balsamic vinegar, 1 tbsp oil, salt, and pepper.

   • Add portobello caps gill-side up; marinate 15 minutes, flipping halfway.

2. Sauté the filling.

   • Heat remaining 1 tbsp oil in a skillet over medium heat. Add onion; cook until translucent.

   • Add sliced mushrooms; sauté 5 minutes until golden.

   • Stir in garlic; cook 30 seconds until fragrant. Add spinach and cook until just wilted. Season with salt and pepper.

3. Stuff and grill.

   • Preheat grill or grill pan to medium-high.

   • Place portobellos gill-side down directly on grates for 3 minutes to char slightly. Flip and fill each cap with mushroom-spinach mixture. Top with cheese.

   • Close lid and grill 3–4 minutes until cheese melts and portobellos are tender.

4. Assemble burgers.

   • Toast buns lightly on the grill.

   • Layer lettuce, stuffed portobello, tomato slice, avocado, and onion on the bottom bun. Top with the crown and serve immediately.

Notes for Perfection

• Cheese alternatives: Blue cheese or goat cheese add tang.

• Make vegan: Swap cheese for dairy-free alternative and use tamari instead of balsamic.

• Side pairing: Serve with sweet potato fries or a crisp green salad.

These stuffed portobello burgers pack umami punch, satisfying vegans and meat-eaters alike. Their gourmet presentation and rich flavors make them a crowd-pleaser at any table.