Take a pan with which you roasted your meat (such as Slow Roast Lamb).
Spoon off excess fat.
Put the roasting pan (from the Slow Roast Lamb) onto hob and bring to a rapid boil.
Add the mustard, mint leaves and some crème fraiche, and some honey for taste.
Add the stock.
Season and pass through a sieve into a gravy boat. Serve with the meat.