Drain meat juices from meat and put to one side in a jug.
Put a lump of lard in a saucepan and if you can skim any fat off the top of the meat juices add that now (I usually let my meat juices sit in a jug while the potatoes are in the oven so by the time it’s “gravy time” that fat has risen to the surface).
Melt the fat and when it’s all liquid add a few tablespoons of flour and mix to make a paste.
Once paste is made slowly add meat juices allowing the mixture to thickening back up between adding more liquid.
Add some gravy browning to give some colour.
Once you’ve used all the meat juices add some water from cooked vegetables and make up some gravy granules/an oxo cube if you need more liquid.
Once you’ve got the desired amount of gravy, bring to boil for a few minutes, season and add a splash of balsamic vinegar.
Decant into a serving jug through a drive to catch any rogue bits of meat/veg or lumps 
Hey presto, best gravy ever!