Into a saucepan pour the olive oil, the juice of a small lemon and about a tablespoonfull of wine vinegar. Then put in a lot of freshly ground black pepper, a spoonful of salt, 3 cloves of garlic put through a garlic press (or chopped very finely if you haven’t got one), the mint leaves roughly chopped up, the mushrooms sliced and the onions peeled and cut into very thin rings. Mix all this up with a spoon and put on a very low heat with the lid on for not more than 10 minutes. Pour into a serving dish and cool in the fridge. Serve with brown bread so that greedy people can mop up any remaining juice with it.