Stock is very easy and very hands-off. Anyone can make it. Lots of recipes for stock call for a lot of vegetables that are chopped, etc. My way is easier and much more convenient;-)
Whenever I cook, I save all the vegetable scraps. I put them in a ziploc bag in the freezer. When the bag is full, I make stock. EASY!
Here is a list of the usual things I save:
carrot peel
carrot stems/ ends of the carrot
celery leaves
celery hearts
onion peel and roots
parsley stems
thyme stems
bell pepper stems/ pulp membrane
pieces of garlic
shallot roots and peel
potato peel
egg shells (make sure they are clean)
You can use almost any vegetable. Don't use potatoe chunks or squash, as it can make the stock cloudy. Tomatoes can make the stock acidic, but if you are going to use the stock in a recipe that has tomatoes (ie tomato soup) then, go ahead! Basil and cilantro will give the stock very distinct flavors, which isn't good in every recipe. Don't use fruit or anything citrus.
When you have enough scraps, put everything in a large heavy bottom stock pot and fill with cold water. I usually add a few things for flavor: a piece of garlic, a few peppercorns, a bay leaf, and a pinch of red pepper flakes. If the stock is lacking in herbs, I will add a little dried parsley and thyme. Let your stock simmer, uncovered, for about three hours. Don't boil or stir stock- the simmering will do that for you. If you let it boil or stir it, you can make it cloudy.
I like to use yellow onion peels in my stock. It gives it a beautiful color (obviously more so than white onion). Keep in mind the bell peppers will turn the stock color, as will red onions. If you are trying to make brown stock, stay away from red onions, red peppers, and tomatoes.
NEVER EVER salt your stock. Always salt recipes at the end. Salt flavor cooks out the longer you cook something, so adding salt in the beginning is a good way to increase your sodium intake by quite a bit.
When the stock is done, it should be clear and a brown or red color, depending on the veggies you use. Let the stock cool a little and strain, using a colander, into another pot. Then strain using cheesecloth into another container. You can refrigerate stock for 7-10 days of freeze for months.
For chicken stock, I add either a raw piece of chicken or the leftover carcass (I hate that word). If you use raw chicken, you will need to simmer the stock for about 5-6 hours, so the chicken is cooked completely before you strain it. Bones add the most flavor, so when you can, use bones as well as the meat.
For beef broth, it's best to drizzle the beef and beef bones with oil and roast in the oven on 350 for about an hour, then add to the stock. Simmer that for about 5-6 hours, the same as chicken.
I also throw some apple cider vinegar in it sometimes for a kick. Just a little gives a lot it a lot flavor.