Ingredients

• 3 tablespoons olive oil
• 1 1/2 tablespoons balsamic vinegar
• 1 teaspoon dried basil
• 1 teaspoon dried parsley
• 1 teaspoon dried thyme
• Pinch of kosher salt
• Pinch of freshly ground black pepper
• 6 portobello mushrooms, cleaned
• 6 brioche or gluten-free buns, sliced in half
• 6 slices beefsteak tomato
• 6 slices red onion
• Butter lettuce leaves, for serving
• Suggested toppings: mustard, mayonnaise and ketchup

Instructions

1. Put the olive oil and balsamic vinegar in a pitcher. Add the basil, parsley, thyme, salt and pepper and whisk together. Pour the mixture into a resealable plastic bag. Add the mushrooms, seal the bag and toss around to coat. Grill immediately, or leave the mushrooms in the marinade for up to 2 hours.
2. When ready to cook, heat a grill or grill pan to medium high. Cook the mushrooms until lightly charred and tender, 4 to 5 minutes per side. Toast the buns cut-side down until golden, a couple of minutes.
3. Serve the mushrooms in the buns with sliced tomato, red onion, butter lettuce, mustard, mayonnaise and ketchup.