Place your Gammon into the inner pot on top of the trivet, then add the onions, carrots and spices.
Pour 2L of ginger beer over the gammon, then top up the liquid to the “max” level with water.
Secure the lid and select Pressure Cook and set the timer to 0 minutes (or 1 minute if using a Duo Evo Plus or Pro.) Be sure to turn off “Keep Warm”. Press Start.
Once the gammon has come to pressure, allow the pressure to naturally release and leave the gammon to completely cool in the liquid overnight (7-8 hours).
When ready to glaze, pour 250ml of ginger beer into a pan and heat until the ginger beer has reduce by 70%, into a sticky glaze.
Add the reduced ginger beer into a bowl with the Dijon mustard, and mix until combined. Set aside.
On the day of serving: Heat the oven to 220° C. Remove the gammon from the cooking liquor and gently cut off the hard skin, leaving a nice white fatty layer on the gammon. Score the gammon fat at 1cm intervals, then place the gammon in a roasting dish. Brush the meat with the ginger and mustard glaze and cook until the fat is browned, and the gammon is sticky and glazed.
*Be sure to use a brand like Fever Tree for your gammon, which is lower in sugar, uses ginger extract, and yields a pleasing, subtle ginger sweetness. Brands with sugar alternatives can turn bitter on glaze reduction.