This step is optional. If I'm in a hurry, I will certainly skip it. However, the depth of flavor that roasting the bones adds to your broth is exceptional and I encourage you to try it if you have a little extra time to spare.
Preheat the oven to 425℉. Slice 1 or 2 onions in half and place them and the bones on a sheet pan lined with parchment paper. Drizzle a good amount of olive oil over your bones. Generously dress the bones and onions with sea salt. With your hands, rub the salt and olive oil into your bones making sure to get all sides.
When the oven is preheated add the sheet pan to the oven for 15-20 minutes watching and smelling. When they are done they will be golden brown.
Step Two: Adding Bones and Other Ingredients to Pot
Add the roasted (or unroasted) onions and bones to the instant pot. Make sure to let all the oils from the pan drip into the pot as well! Add remaining ingredients. Make sure the instant pot lid is "sealed", and press "soup/broth". This takes 30 minutes of pressure cooking time and 30 minutes of venting time.
When the broth has been completed, it's time to transfer it to the strainer. Prepare your strainer with a pot underneath to catch the liquid. I use a yogurt strainer inside of a pot. I like to do this in the sink, to not make a mess on the counter if you spill a little broth. Then pour the liquid into the strainer. Watching closely to make sure the pot is not overfilling. Toss your bones, compost the bones, or feed the bones to chickens!
Lastly, transfer the broth into quart, 1/2 gallon, or gallon-size mason jars with lids. I leave my jars of broth on the counter to cool before transferring them into the fridge.