1. Rinse the mushroom caps in cold water and dry it.
2. Put into vinaigrette with the stem side turned upwards.
3. Add dressing into caps and keep it for 5-10 minutes.
4. Grill the stuffed mushrooms for 8-10 minutes with the stem side turned upwards.
5. Turn the mushrooms and grill for another 8-10 minutes until the mushrooms get cooked through.
6. Slice the mushrooms into individual servings.