We try to have as little waste as possible at our house, and one way we do that is by saving our vegetable scraps for broth. Broth is handy to have around (in the freezer or the fridge) for making grains, soups and stews.
While we’re cooking throughout the week we keep a gallon storage bag in the freezer, and whenever we’re cooking, take it out and add the scraps to it - the carrot tops (and bottoms), onion skins, avocado pits, kale stems, ginger skin etc . We like to encourage our customers to add any vegetables they’re just not going to get around to using, to the stock bag.
When the bag gets full, which could happen after a week or two depending on how often you cook, add all the contents into a large stock pot (recently Ive been adding a tablespoon or two of apple cider vinegar in addition to the vegetables), cover with water and bring to a boil, then reduce to a simmer. I like to have it simmer until the wonderful brothy aroma fills the kitchen, which is somewhere in the arena of 30-40 minuets. Strain broth using a fine mesh strainer, compost solids, and let the broth cool for around an hour. We store the broth in quart jars; they keep in the fridge for a week or you could freeze them for up to six months.