Portobello Burgers with Pesto Mayo

Combine all marinade ingredients in a jar with a tight fitting lid.  Screw lid on tight and shake until mixture is thoroughly combined.  Pour marinade over all prepared mushrooms on baking sheet.  Cover loosely with plastic wrap and let marinate for at least 30 minutes, turning every 10 minutes.

Stir pesto and mayonnaise in small bowl to blend; set aside.

Preheat grill or barbecue to medium-high heat. 

Slather each roll with pesto mayonnaise and place 1 mushroom on each roll bottom. Top each with lettuce, tomato and onion. Press roll tops over and serve.

1/4 cup purchased pesto (used: Bertoli)
1/4 cup real canola mayonnaise
4 sweet onion rolls (used: local deli brand)
4 portobello mushrooms, stems cut off flush with base of cap
Tomatoes, sliced
Onion, sliced
Lettuce leaves
4 slices provolone cheese

Balsamic Marinade:
½ cup balsamic vinegar
2 T hoisin sauce
2 T olive or canola oil
1 T packed brown sugar
4 cloves garlic, minced
2 t fresh thyme, minced
1 t freshly ground black pepper
½ t freshly ground sea salt

Remove stems from mushroom caps and wipe caps clean with a clean damp kitchen towel.  Place caps onto a large baking sheet with sides.

Combine all marinade ingredients in a jar with a tight fitting lid.  Screw lid on tight and shake until mixture is thoroughly combined.  Pour marinade over all prepared mushrooms on baking sheet.  Cover loosely with plastic wrap and let marinate for at least 30 minutes, turning every 10 minutes.

Stir pesto and mayonnaise in small bowl to blend; set aside.

Preheat grill or barbecue to medium-high heat. 

Place mushrooms on preheated grill, rounded side up for about 4 minutes. Turn mushrooms over. Cover and grill until mushrooms are tender, about 4 to 6 more minutes. 

Place buns open face down onto grill to warm and toast.

Place 1 slice of cheese on top of each mushroom and cover until melted.  Serve immediately.

Slather each roll with pesto mayonnaise and place 1 mushroom on each roll bottom. Top each with lettuce, tomato and onion. Press roll tops over and serve.