In a stock over medium-low heat, render the diced bacon until the pieces of bacon are crisp. Remove bacon pieces from the rendered fat in the pot, and set aside on a paper towel lined plate.
Add the carrots, celery, and parsnips to the rendered fat in the stock pot and cook over medium heat for 2 to 3 minutes, stirring occasionally.
Add in the cabbage and leeks and cook for an additional 2 to 3 minutes or until wilted, stirring occasionally.
Add in garlic, and cook until it is fragrant.
Add in the stout to deglaze the pan. Then add in the potatoes and vegetable stock.
Grind fennel seed, dill weed, and mustard seed (a mortar and pestle can be used), and add to the stew.
Add in bay leaves and bring stew to a simmer.
Cook stew until the potatoes are fork tender.
Transfer ¼ of the stew to a blender, and mix until smooth.
Run the mixture through a strainer to make it smooth, and add it back into the stew as a thickener.
Add in heavy cream and parsley, and bring back to a simmer until thickened.
Add in crispy bacon pieces, and season with salt and pepper to taste.
Serve with Irish Soda Bread (optional).
