As a retired chef (13 good restaurants over 3 global sites)..with no illusions, I have an ‘essential’ view.
It’s easy. Save ALL cut-offs from vegetables except cucumber, celery leaves (bitter), potato peels (rot) , or anything you don’t want to ‘enhance’ you flavor with….say, cinnamon.
Save ALL bones, no matter what carcass – they will add flavor to you stock if you roast them blind to start. This also helps them become brittle so you can ‘crack’ into the marrow – HUGE!
The trick is this: save all you cut-offs of veg and/or roasted bones in the freezer. When you have enough, start cookin’! Domestic takes time and a larger than normal pot; just cover with water, add mixed herbs and black peppercorn (NO SALT) and bring to boil. Vaguely cover and simmer for as long as you can. If you DO have bones in there, you should either be able to crack them or bamboo-stick them to get the marrow out to add to your stock.
Because I’m domestic now, I put my covered stock out on the balcony in the cold overnight. Next day, clear off the fat, strain through a fine sieve incrementally, and freeze as ‘stock’ (mine get moved to gravy or sauce depending on my use).
Chickens are wonderful as a boiled meat. No need to add anything but water – use a thermometer to see when it’s cooked. It keeps deliciously moist and even; I often prefer it to ‘roasted’ or fried. The stock it leaves over (because you have to cover the beastie with water – I chop mine in half between the breasts and things – obliquely) means you can add all your reserved frozen veg cut-offs etc to this mix, low-boil for a few hours (with semi-lid) and reduce to your own freezer space.
I actually enjoy a delicious chicken broth made by simmering chicken scraps/bones, a stick or two of cinnamon, healthy pinches of coriander and cumin, an onion or two sliced in half, a heavy pinch of dried marjoram, and one or two dried pasilla chiles.
Among other things, that’s my go-to base for pozole.