Here’s what you’ll need:
- 4 Portobello mushrooms
- ½ cup teriyaki marinade or sauce
- 4 hamburger buns
- 4 slices smoked gouda cheese
- 4 leaves butter or curly lettuce
- Pickled red onions (optional)
- Cut or break the stems off the Portobello mushrooms and scrape out the gills.
- In a bowl or large re-sealable container, toss the mushrooms with 6 Tbsp of the teriyaki sauce until thoroughly coated.
- Cover and marinate in the fridge for about 30 minutes.
- Oil and prepare the grill for direct cooking over medium-high heat.
- Grill the mushrooms for about 4 minutes each side, until tender. Make sure to keep the grill covered as much as possible to ensure even cooking.
- Place a slice of smoked gouda on each mushroom. Cover and cook until cheese is melted.
- Toast the buns on the grill until golden brown.
- Remove and spread the remaining teriyaki sauce on the bottom buns.
- Layer a mushroom cap on each bun and top with a piece of butter lettuce and picked red onion. Serve immediately.