1. Wipe the mushrooms with a damp paper towel. Cut off and discard the shiitake stems, if using. Quarter all the mushrooms and place in food processor. Pulse until coarsely chopped.
2. Heat the oil in a wok. Add the garlic and sauté over low heat until soft.
3. Add the chopped mushrooms, raise the heat, and stir for one minute. Remove to a bowl.
4. Season to taste with the soy sauce, lemon juice, salt and pepper. Stir in the marjoram and cool.