Potatoes In A White Sauce

Though I promised myself that I would not take food from London to the French house or vice versa it was never likely that I would be able to entirely resist transporting Asian ingredients like kecap manis to France - in order to make ostrich sauce to go with grilled duck which worked a treat not just with duck but also with barbecued toulouse sausages as well. The return journey back to London is seldom made without bringing at least one thing, more often than not duck related. This last trip we had a couple of very enjoyable nights perfecting the technique for cooking magret on the barbecue till the skin was utterly crisp, all fat rendered, and the flesh was rare and flavoursome. Served with tomatoes and fat spring onions also cooked over coal we felt we'd made serious inroads into that particular delight.

The local supermarket sells local duck breast individually sealed in packs of three so I had two to bring back, along with walnuts, a twisted string of local garlic and a pot of friton - the duck equivalent of pork scratchings which, warmed through make a lovely topping for salads. Barbecue in London this week was not a possibility - cold wet winds etc - so I pan fried one of the breasts instead. Most often I cook potatoes in duck fat with a little/lot of garlic till crispy to go with it and a little salad to mop up the juices.

This time though I had found a recipe in Jeanne Strang's sublime Goose Fat & Garlic that she recommended to go with magret or other grilled meat and I was intrigued. It involved frying off the potato briefly then cooking them in stock scented with a bouquet garni till tender and finishing with an egg yolk beaten with vinegar to thicken the juices. The vinegar adds a slight acidity that cuts through the fat really well.

Bouquet garni add subtle and sublime depths to many dishes. Though all cuisines use bundles of herbs to flavour soups and stews the term comes from the French as they moved away from using the more expensive spices that had been common in the Middle Ages. Originally the bouquet would have included a rasher of bacon - for the fat and the flavour, no doubt, as well as thyme, parsley and bay. There is no hard and fast rule for what must be included - just what you have to hand that will work well with the other ingredients. For this I used a sprig each of rosemary, thyme, parsley and tarragon with a bay leaf for luck.

Potatoes in a White Sauce

500g waxy potatoes, quartered

1 medium onion, finely chopped

1 tablespoon duck fat or olive oil

1 tablespoon plain flour

Bouquet garni

350ml fresh chicken or vegetable stock

1 egg yolk

1/2 tbspn white wine vinegar

Melt the duck fat in a medium pan and fry the potatoes till just tinged with brown. Stir them occasionally to be sure they don't stick. Add the onion and keep stirring and frying for a few minutes till the onion becomes translucent. Sprinkle over the flour, mix in thoroughly for a minute then slowly add enough stock to cover. Bring to a simmer then cover and reduce the heat to very low.

Cook for about twenty minutes till the potatoes are tender. Remove the bouquet garni and throw it away. Whisk the egg yolk with the vinegar and stir into the hot potatoes to thicken the juices. Season and serve.

Be sure to use waxy potatoes for this - floury ones will collapse to sludge which would be a real shame. We had some of the sauce left after serving this so it's in the freezer for next week when I fancy it with grilled chicken and mashed potatoes. Aleady my thoughts turn to autumnal dishes...