Heat six tablespoons of the olive oil in a frying pan, fry the chopped garlic and chilli for one minute, then add the mushrooms and fry for a further 2-3 minutes, or until cooked.
Stir in the parsley and marjoram and season with salt and freshly ground black pepper.
Meanwhile, toast the slices of bread on both sides. Rub each piece of bread lightly with the whole garlic clove and brush with the remaining olive oil, then slice into individual servings if needed. Spoon over the mushrooms and serve.