• Clean the mushrooms with a damp cloth or kitchen towel to wipe away dirt. Remove the stems. Add them to a baking sheet.
• Add olive oil, balsamic vinegar, thyme, oregano, garlic, salt and pepper to a small mixing bowl. Whisk to combine. Brush mixture over mushrooms evenly. Flip and repeat the process. Leave to marinade at room temperature uncovered for 30 minutes.
• Meanwhile, prepare the caramelized onions by heating a skillet over medium heat. Once hot, add the olive oil, onions and soy sauce. Cook for 10 minutes, stirring occasionally, until brown and soft.
• Return the same skillet used to make the caramelized onions to medium-high heat and add the mushrooms. Saute for 3-6 minutes each side until mushrooms are golden brown on the edge and soft. While cooking, brush more marinade for extra flavor.
• Prepare the buns by toasting in the skillet. Slice the tomatoes, and wash, pat dry the lettuce or greens, if using. Set aside.
• To serve your mushroom burgers, add an optional spoonful of cheese cream to each bottom bun. Top with tomato, lettuce, mushrooms, and onions. If desired, add more cream on top of the bun.
• Enjoy immediately.

To make the vegan cream cheese (optional)

• Blend all the vegan cream cheese ingredients until smooth on a food small processor, add to a small skillet and cook for 6 to 8 mins at medium heat to thicken. Taste and adjust salt and flavor. Cool the sauce for a few mins. It will thicken when cooled.