A simple, delicious way to reduce waste AND save some money at the supermarket.
First, some tips:
Keep a large (I use gallon-size) ziploc bag in the freezer and toss any leftover veggie scraps into it until it's full. Think broccoli stems, celery ends, carrot tops, onion skins etc.
If you're making stock, leftover rotisserie chicken carcasses (or other bones) are perfect for this. Just make sure you make the stock within a day or two after eating the chicken.
Got some fresh herbs that are lingering in your fridge? We call them "on-the-verge" herbs and they're perfect for this method.
Save your takeout containers (you know, the round ones that egg drop or wonton soups come in). They make great storage, especially the 1 quart size since most stocks are packaged in quarts.
When your bag of veggie scraps is full, empty it into a large stock pot along with your leftover bones (if using) and herbs. Add a halved onion and a few cloves of garlic and add water until everything is submerged. Cover with a tight fitting lid and bring to a boil. Reduce heat and simmer covered for about an hour.
Place a collander over a large bowl and empty contents of stock pot into collander to drain. Stock will collect in the bowl. Feel free to give everything a good press while in the collander so you get every bit of stock. Pour stock into quart size containers* leaving room at the top for expansion in the freezer.
Allow to cool before putting lids on and freezing.
*For smaller portions, fill silicone ice cube trays with stock and freeze. When frozen, remove stock cubes and store in a ziploc.
That's it! Depending on the amount of veggie scraps and water used, you can get anywhere from 3-4 quarts of homemade stock in less than 90 minutes...with just a few minutes of hands-on time.