Start by soaking the ceps in 250ml warm water for 30 minutes. When they are all soft, remove them from their soaking water, but keep it for making the sauce. Cut larger pieces of cep in half.
Soak the bread in a cup full of water and when it softens, squeeze it dry. Heat 2 tablespoons of olive oil and soften the onion and garlic gently until soft and turning golden. Put the minced meats and sausage in a bowl with the crumbled bread, half the cooked onions and garlic, the parsley, egg, cinnamon and salt and pepper. Mix everything together thoroughly with your hands. If you have time to let it stand, this improves the flavour.
Take an egg-sized piece of the mixture and roll it into a ball. Continue until all the mixture is used up. Put the flour on a board and roll the meatballs to coat them well. Heat 3 tablespoons olive oil in a large frying-pan over a high heat. When it is smoking hot, fry the meatballs on all sides to brown them.
To make the sauce, heat the remaining onions and garlic in a large frying-pan, stir in the flour and let it brown, then add the tomatoes and chillies and pimentón. Stir together, put in all the meatballs and add the water from the mushrooms and 250ml stock (or water with half a stock cube dissolved in it). Season lightly with salt.
Heat, cover and simmer for 30 minutes. Taste the sauce and add a teaspoon of sugar if needed, but no salt at this stage. Add the olives and mushrooms and more water if the sauce is getting too thick, there should be plenty of it. Simmer for a further 30 minutes, taste for seasoning and enjoy the deep flavours of this magnificent dish.