Preheat the oven to 200C/400F/Gas 6.
For the quail, place the port and beef stock into a pan and bring to a boil. Reduce the heat and simmer for 15-20 minutes until the liquid has reduced by two thirds.
Heat a frying pan until hot and add 25g/1oz of the butter.
Season each quail with salt and freshly ground black pepper and stuff the cavity with a sprig of thyme. Place each quail breast-side down into the frying pan. Fry on all sides until golden all over (you may need to cook the quails in batches so as not to overcrowd the pan).
Heat a lidded casserole dish until hot and add 25g/1oz of the butter. Add the leeks, turnips, carrots, fennel and garlic and fry for 2-3 minutes to soften.
Place the quail on top of the vegetables and pour over the reduced sauce. Cover the casserole with the lid and place into the oven to cook for 15-20 minutes, or until the quail is completely cooked through.
For the risotto, place the chicken stock into a clean pan over a medium heat and bring to a gentle simmer.
Meanwhile, heat a saucepan until hot, then add the onion, garlic and 25g/1oz of the butter and cook for 2-3 minutes, until softened but not coloured.
Add the rice and cook for a minute, stirring well to coat the rice in the melted butter.
Add the Muscat and simmer to reduce the liquid by half.
Add the warm stock, one ladleful at a time, stirring until nearly all the stock is absorbed before adding the next ladleful. Cook until all the stock has been added and absorbed and the rice is just tender.
Add the grapes, the remaining 25g/1oz of butter and the parmesan. Stir to combine and season, to taste, with salt and freshly ground black pepper.
Meanwhile, remove the quail from the casserole and set aside to rest in a warm place. Spoon equal portions of the vegetables among four warmed serving plates.
Place the casserole over a high heat and boil the sauce to reduce the liquid by half. Add the final 25g/1oz of butter and season, to taste, with salt and freshly ground black pepper.
To serve, place one quail on top each plate of vegetables and spoon over the sauce. Place a spoonful of risotto alongside.