First, make the sauce. Bring the white wine to the boil and pour it on top of the dried mushrooms. Cover with cling film and leave to soak and rehydrate for 1 hr. After this time, pass the wine through a fine sieve into a saucepan and put the mushrooms to one side. Add the shallots and garlic to the wine. Put the pan on a medium-high heat until the wine has reduced by two-thirds, and the shallots are soft and translucent. Add the tied-up sprigs of thyme, the mushrooms and double cream. Bring the cream to the boil and gently simmer until it has reduced by a third. Remove from the heat, season, pour in the Sherry and turn off the heat until serving. Can be made 2 days ahead. Heat oven to 220C/200C fan/gas 7. Stuff the cavity of each poussin with 2 garlic cloves, 4 sprigs of thyme and a piece of lemon peel. For neat presentation, you can now tie the poussin legs together, but this isn’t essential. Smear the butter over the poussins, put in a shallow roasting tin and cook for 30-35 mins until the legs easily come away from the bird, or until a digital cooking thermometer reads 75C when inserted in the breast. Take out of the oven, baste with the buttery cooking juices and leave to rest for 15 mins.