Roast quail with creamy horseradish cabbage, smoked bacon and chestnuts

Name: Roast quail with creamy horseradish cabbage, smoked bacon and chestnuts
Yield: Serves 4
Ingredients: 100 ml (3½ fl oz/scant ½ cup) Madeira; 300 ml (10 fl oz/1¼ cups) brown chicken stock; Sea salt and freshly ground black pepper; Sea salt and freshly ground black pepper; 4 tbsp sunflower oil; 1 small Savoy cabbage, blemished outer leaves removed; 100 ml (3½ fl oz/scant ½ cup) double (heavy) cream; 2 tbsp creamed horseradish; 200 g (7 oz) chestnuts (frozen or vacuum-packed); 200 g (7 oz) chestnuts (frozen or vacuum-packed); 350 g (12 oz) new baby potatoes, unpeeled; 150 g (5½ oz) smoked bacon lardons; 40 g (scant 1½ oz/3 tbsp) unsalted butter, plus 1 tbsp for reheating the cabbage leaves; 4 large quails, approx 550 g (1¼ lb) each; 200 g (7 oz) chestnuts (frozen or vacuum-packed); 40 g (scant 1½ oz/3 tbsp) unsalted butter, plus 1 tbsp for reheating the cabbage leaves