Heat the Instant Pot on sauté and add your fat and brown the meat in batches, without crowding. Remove as needed to brown the rest.
Add the onions and sauté until they have some colour.
Add the thyme, rosemary, bay leaf, broth, wine, and garlic along with the meat and onions. Put the lid on, set to sealing and cook for 30 minutes on high pressure. Let it naturally release for at least 20 minutes before flipping the vent; doing a quick release can make your meat tough/dry.
After the first time is up, check that your meat is tender. It does not need to be fall apart tender but if it still feels like shoe leather…it should maybe go a bit longer on its own…
Then add in your celery, carrots, potatoes, and optional parsnips and beets.
Cook on high pressure for another 15 minutes and another natural release.
When the time is up, check that your vegetables are fork tender and easily mash if you press a chunk against the side of the pot with a fork.
If you’d like to add any of the frozen vegetables, do so now. I do it at the end so they maintain their bite and don't become mush.
We like our gravy thick in our stew, so this next step is optional, but really quite delicious. Omit or use cornstarch to keep it gluten-free.
Put the flour and water in a canning jar with a lid, shake it up well, then stir it into the stew. Turn to saute and cook until desired thickness and serve.