Remove the stalks from the spinach and wash thoroughly in several waters. Drain and place in a medium-sized saucepan containing a tumblerful of fast-boiling salted water. The spinach will wilt as the water returns to the boil; remove it with a slotted spoon and refresh under cold running water, then drain. (Like all green vegetables spinach should be cooked uncovered and refreshed in cold water to keep its natural green colour).
Remove the fat, then skin the kidney and cut it into walnut-sized pieces. Put the sweetbreads into 1 litre (1¾ pints) unsalted cold water and bring slowly to simmering point. Simmer for 5 minutes then refresh under cold running water and drain. Remove the gelatinous membranes and any fatty bits carefully. Cut into walnut-sized pieces. Season both kidneys and sweetbreads with salt and pepper.
Squeeze the remaining water from the spinach with your hands. Heat 15g (½oz) of butter in a saucepan until the foam has subsided, put in the spinach and stir well with a fork. Season with salt and pepper and keep hot.
Heat a nut of butter in a frying-pan, and when the foam begins to subside put in the seasoned sweetbreads and let them cook for 6 minutes, allowing them to turn pale golden. While they are cooking, heat a nut of butter and a trickle of oil in a frying-pan, and when it begins to brown throw in the seasoned kidneys (take care that you don’t get splashed with spitting fat). Sauté the pieces of kidney for 3–4 minutes. Then drain both the sweetbreads and the kidneys and keep hot in a colander.
Put the dry white wine, together with the chopped shallot, into the pan in which the kidneys have cooked. Reduce over the heat until no more than 2tablespoons remain. Add the half chicken stock cube crumbled up, a good pinch of paprika and the cream, and simmer for 5 minutes. Adjust the seasoning if necessary. The sauce should be just thick enough to coat the back of a wooden spoon lightly.
Put the spinach leaves (1) in the middle of two or three hot plates, spread them out a little and surround them with alternate pieces of kidney and sweetbread. Strain the sauce through a fine sieve and pour it over each piece of kidney and sweetbread, but not the spinach. Serve very hot, and hand any extra sauce separately.