• Clean the mushrooms and remove the stem. Score the top of the mushrooms - I like to do a criss cross pattern. You want the marinade to soak into the mushrooms!
• Place the mushrooms in a dish in a single layer. Whisk together the olive oil, vinegar, worcestershire, garlic powder and a big pinch of salt and pepper. Pour the mixture over the mushrooms.
• Flip the mushrooms a few times so all sides are coated. Marinate for 30 minutes, flipping once or twice during the marinade time.
• Preheat the grill to medium-high. I like mine to be around 450-500 degrees F when I’m ready to grill. While it preheats, make the house sauce.
• When the grill is hot enough, make the burgers. Remove the mushrooms from the marinade and let the rest drip into the pan. Place the mushrooms on the grates. Cover and grill for 5 minutes.
• Gently flip and grill for another 3 to 4 minutes. Add a slice of cheese on top of each mushroom. Cover and grill for another minute.
• To assemble the burgers, top a bun with shredded lettuce. Place the portobello cap on top. Drizzle with the house sauce and top with a slice of tomato. Serve!

house sauce

• Whisk all ingredients together until creamy and smooth and combined. Serve for dipping or as a drizzle sauce. Stays great in the fridge for a week.