In a large mixing bowl, season the pork with the salt, pepper, and garlic; then toss the pork in the flour to coat evenly.
In a 6 qt dutch oven, or stockpot, heat the oil over med-high heat. Shake the excess flour off of the pork and sear, in small batches, until browned. Remove the pork from the pan using tongs, or a slotted spoon, to a bowl or serving dish to hold while you sear the remaining pork.
Once all of the pork has been seared and set aside, add the onions, celery, carrots, parsnips, and garlic to the pot. Sauté until glossy (about 5 minutes).
Deglaze the pan by adding the Guinness and using a wooden spoon to scrape up any bits of cooked on food from the bottom of the pan. Return the pork to the pan, and add the beef broth. Bring to a boil.
While you're waiting for the stew to come to a boil, make a bouquet garni by tying together the thyme, rosemary, sage and bay leaves with kitchen twine. Tie the bouquet to the handle of the pot making sure the twine is going enough to submerge the bouquet.
Once the stew has come to a boil, reduce the heat and cook, covered, over med-low heat for 10 minutes.
Add the squash, pumpkin and potatoes and cook for an additional hour, or until the gourds and potatoes are tender.
Remove the bouquet from the pan's handle and spoon into bowls. Enjoy!