Christmas Ham

 I am going to try to do ham for Christmas lunch.  Apparently the thing is to do a thing called "double cooking".  What is this?

https://www.taste.com.au/recipes/spiced-rum-apricot-glazed-ham/NoDnjPbA?r=recipes%2Fglazedchristmashamrecipes&c=3z148u7a%2FGlazed%20christmas%20ham%20recipes&fbclid=IwAR2JH-qODiE9W_BXjioUgHbcsve_2H7r8oj9qVZcT9N553Z1TYtV-yRJxqE

INGREDIENTS
Ham bone in 
Cloves
Tin foil long roll
Roasting tinfoil pan $3.50 I think

Rum
Good marmalade the one from U.K.
BBQ Sauce

https://www.youtube.com/watch?v=TES_0bf5CL4

Start Time 3:10pm  Temperature 150C

Spiced rum and apricot glaze
370g jar apricot conserve  Use Marmalde
125ml (1/2 cup) spiced rum
2 tablespoons barbecue sauce 

To make the glaze, heat the conserve, rum and barbecue sauce in a saucepan over medium heat, stirring often, for 8-10 minutes or until thickened slightly.