Lamb Rhine Claude

450 g/1 lb Rcine Claude plums, or greengages,
halved and stoned
150 ml/1/4 pint chicken stock
3 tablespoons Creme de Cassis
450 g/1 lb lamb fillet, cut in small medallions
2 tablespoons olive oil
salt
freshly ground black pepper

Put the plums or greengages into a pan with the chicken stock and simmer gently for 5 minutes. Cool slightly, then put into a blender or food processor with the liquid and the Creme de Cassis; blend to a smooth puree. Cook the lamb medallions in the olive oil until evenly browned on all sides; add the plum and Cassis puree to the medallions and season to taste with salt and pepper. Cover and simmer for about 15 to 20 minutes until the lamb is quite tender. Serve immediately. SERVES 4