Preheat the oven to 450°F[230°C/gas mark 8].
If you’re making a jus using lamb trimmings, trim the meat away from the fat on the trimmings and discard the fat. Cut the meat into thin strips, about inch [1.5 cm] on each side. If you’re using lamb shoulder meat, cut it into thin strips. If you’re using stew meat, cut it into cubes or strips about ½ inch [1.5 cm] on each side. Sprea