This is how I make mine for a roast.
After meat and veggies are roasted and fat is drained leaving the juices, I add stock. Let it bubble always stirring.
If it's chicken, I add a good splash of sherry. If you want it thickened use cornflour mixed with a little cold water.
If it's beef, I add a good pouring of red wine and let that reduce in the roasting pan and then add stock and then thicken it.
If it's duck, I add port to the roasting pan, then stock....
Pork? I add white wine, stock and maybe some cream...
I do use KALLO stock cubes as there is no hydrogenated fats, no wheat added either.....
So, basically... always make your gravy in the pan you've cooked the meat in or pour the juices into a saucepan....
My mother always made her gravy starting with flour in the pan and making a roux..... I'm too lazy and use corn flour lol..... :-) xxx