For the parsley sauce
1 litre/1¾ pints water
a generous pinch of sea salt
150g/5oz curly parsley, stems removed
500ml/17fl oz double cream
freshly grated nutmeg
1tsp finely grated lemon zest or to taste
For the guinea fowl
6 guinea fowl supremes
sea salt and freshly ground black pepper
a little light olive oil for cooking
First make the parsley sauce. Put a pan of well-salted water on to boil. Plunge the parsley leaves into the boiling water for 30 seconds. Remove, and refresh in iced water to keep your parsley a beautiful, bright colour. Drain and set aside. Pour the cream into a heavy-based pan and bring almost to the boil. Turn down the heat and allow to bubble to reduce the cream by about a third. Add the blanched parsley leaves and boil for a moment longer. Remove from the heat and purée in a blender until you have a beautiful, fine texture. Add a generous grating of nutmeg and the lemon zest, season well with salt and a good grinding of pepper. Keep the sauce warm.
For the guinea fowl, heat the oven to 220C/425F/Gas7. Season the bird generously with salt and pepper all over. Place a heavy-based frying pan over a medium to high heat and warm until smoking. Pour in about a tablespoon of the olive oil, then brown the guinea fowl in batches. Lay 2 in the pan, skin-side down and leave to colour for 3 minutes, resisting the temptation to prod or stir them. Transfer to a baking tray (without turning) and brown the rest of the supremes.
Finish cooking the guinea fowl in the oven for around 8 minutes, or until the skin is crisp and crunchy and the breast meat is succulent, moist and cooked through. Leave to rest in a warm place for 5 minutes.
Arrange on warm plates and ladle the parsley sauce generously over the top. Scatter over the remaining chopped parsley and serve immediately.