While there are some gluten-free options out there for chicken stock/broth, once you add multiple food sensitivities it gets particularly difficult to find something safe. I learned how to do my own broth when we were testing to see if my partner was also reacting to nightshade plants such as tomato and pepper. Paprika is both ubiquitous and unlabeled as a seasoning ingredient in a LOT of commercially prepared foods.
Start your Scrap Bag
Step one is to gather ingredients. I use a gallon ziplock bag in the freezer to collect scraps. You want the bones and other leftover cooked scraps (e.g. skin, cartilage, etc.) of chicken meals. Breaded pieces are fine, but if you cook something with a strong seasoning (like mole or curry) then rinse the scraps before adding them to the bag. This is a good project for the remains of a whole roasted bird. Every year after the Thanksgiving turkey had been disassembled, my mom would turn the rest into homemade turkey noodle soup, and freeze some of the stock for future recipes.
In addition to chicken bones you should add veggie scraps and ends to your bag that would work well in a chicken soup. This includes carrot and parsnip heads and tips, mushroom stems, green onion roots, celery trimmings and root pieces, the tough but not papery inner peel of onions, etc. Don’t add herbs (too delicate) or a lot of strong flavors like peppers (unless you want a whole batch of peppery stock!). I found that the tough main stem of a cauliflower bunch works well in moderation.
It will seem at first like your scrap bag can’t possibly fill up quickly, and depending on your eating habits you may need to make a point of preparing food that will add to your scrap bag. We started eating chicken leg quarters instead of breasts to save on our grocery bill, which gave us enough scraps to make stock and soup once a month.
You have enough bones and other scraps when there is enough to fill your cooking container. I use an 8-quart slow cooker, so when I have about two gallon ziplock bags of scraps in the freezer, I turn it into stock.
Make the Stock
You can use a slow cooker and let it simmer all day, or cook it in a covered pot on the stove for 4-5 hours.
Add the contents of your scrap bag to your cooking pot and add enough water to cover everything. Add two dried bay leaves (optional) and 1/4-1/2 tsp salt. Cook covered on the stove for 4-5 hours, or in a slow cooker on high heat for 8-10 hours.
Let it cool enough to handle without scalding yourself. Pour through a mesh strainer or cheesecloth into a separate container. Discard the cooked scraps, and place the stock in the refrigerator overnight to cool. Turn it into soup or freeze in freezer-safe containers within 3 days. Use in any recipe that calls for chicken stock or broth.