whatever you use to cook your meat in (frying pan, oven tray etc) will catch the juices from the meat, even if there arent many. Chefs 'de glace' the pan, which basically means they use some liquid to stir in with the meat juices.
when the meat is removed, heat the juices either in the pan or on the tray by using the hob. then add a bit of flour to soak up the juices- make sure you stir it so it doesnt burn but dont add too much. when all the juices and flour are mixed and look like thick lumpy wallpaper paste, then add some of the juices from any veggies you've cooked.
(If you dont have veg juices, use some stock but juices from a mixture of veg are best - e.g carrots, potatoes, peas, greens etc.)
Transfer your basic gravy to a saucepan and gently heat while whisking to get rid of any floury lumps. the flour will start to thicken the gravy, and then use a little bit of gravy browning to add the colour to the gravy. taste and season with salt and pepper if needed. then simmer to cook the flour but dont boil it.
If you want minted gravy, add a little bit of thick mint sauce to the gravy at the end and heat through so the flavours infuse.
It sounds difficult but it really isn't and tastes so much better than granules which are the root of all evil in my books ;-) hope this helps - good luck!