Start by selecting the right kind of mushrooms - since you are marinating them, you will require a meaty, substantial type of mushroom. Use large button mushrooms, as these work best for this purpose, but you can also use portobello mushrooms.
Now, cut the mushrooms into small sized pieces using a knife or a cutter. If you are interested in marinating baby mushrooms, do not chop them up too small - you can simply halve them, or even leave them intact. Once you have cut the mushrooms, place them in a bowl.
Next, add chopped chives to the bowl of mushrooms. Mix the mushrooms and chives for a short while, and then set aside. Meanwhile, make pressed garlic using a garlic press. Add finely chopped fresh basil to the bowl containing the mushrooms, and then add in the pressed garlic.
In another bowl, add olive oil, salt, Tabasco, dried parsley, dried oregano and cider vinger. Mix the ingredients thoroughly until the required texture is achieved. Add some water to the mixture if you think it is too thick. Now, pour this mixture into the bowl containing the mushrooms.
You will be required to allow the mixture to marinate for at least 30 to 40 minutes for best results. Stir the mushrooms to distribute the dressing evenly. Keep the marinated mushrooms in a refrigerator before serving to your guests.