For the eggs, tip the onions into a pan over a low heat with the oil and a pinch of salt, and gently cook for 2 hours until really soft and dark. Drain the onions into a bowl through a fine sieve, discarding the oil. Heat the cream and cheese together over a low heat, stirring until the cheese has melted and the mixture is smooth. Season to taste, then add the onions and eggs, and stir quickly until you have creamy scrambled eggs. Keep warm.