This week's dish is a nourishing winter soup best made with white onions rather than the more common brown-skinned yellow onion on account of their milder and slightly sweeter flavour.

When buying onions, the best will be firm and have a crackly outer skin and a mild scent. If the smell is overwhelming the onion is probably starting to spoil. Onions are best kept in a slightly cool, dark place, but certainly not the fridge, since they tend to spoil the flavour of other foods in concealed spaces.

Duck eggs, available at most delicatessens and farm shops as well as some supermarkets, are fairly large compared to those of hens, making them easily distinguishable. The shell is also much tougher. Everything you do with a hen egg can be done with a duck egg – including scrambling, poaching and baking. A duck egg will generally taste richer than a hen egg and the yolk will be brighter.

White onion soup with poached duck egg and belLota ham

Serves 4

6 large white onions

50g butter

1 clove of garlic, sliced

100ml white wine

500ml chicken stock

100ml double cream

30ml white vinegar

4 duck eggs

100g sliced bellota ham

Peel, halve and slice the onions as finely as possible, then melt the butter in a large pan over a low heat. Add the onions and season lightly with salt, stirring frequently to prevent them from colouring. Once the onions are soft and translucent add the wine, turn up the heat a little and simmer until well-reduced. Add the stock, bring to a simmer and cook over a low heat for 15 minutes.

Take the pan off the hob and puree the soup in a blender with the cream and some white pepper. Taste and adjust the seasoning as required, then pour the soup into a clean saucepan and keep warm.

To poach the eggs, bring two litres of water to a simmer in a deep pan and add the vinegar. Crack each egg on to a small saucer. Whisk the water so it swirls in a clockwise direction then quickly drop the eggs into the pan one at a time. The movement of the water will wrap the white around the yolk. Poach the eggs for 4 minutes then remove on to a dry cloth.

To serve, pour the soup into warm bowls, add an egg to each and finish with a slice of bellota ham.

Fresh and pure, this elegant wine has a bouquet of floral minerality followed by flavours of green citrus.

2010 Hautes-Cotes de Beaune, Domaine Delagrange, Burgundy, France (L'Art Du Vin, £13.80)

The Honours, 58a North Castle Street, Edinburgh. Visit thehonours.co.uk or call 0131 220 2513.