Heat oil on medium high in large saute pan. Season meat well with salt and pepper and dredge in flour. Brown meat in pan and transfer to a large dutch oven. Add more oil to the pan if necessary and cook onions for about 5 minutes. Add mushrooms and minced garlic and cook for an additional 3 minutes. Add 1/2 cup of the Guinness and bring to a boil, scraping up browned bits. Season your veggies with salt and pepper while sauteing them. Add to the dutch oven.
Add the remaining Guinness, bay leaf, herbs, tomato paste, Worcestershire sauce, and beef stock to the pot. Bring to a simmer over medium low and cover for 40 minutes. Add potatoes, and carrots. Cover and continue to simmer for 20 minutes.
Thicken stew with a little cornstarch and water if needed. Taste and season if needed. Drop dumpling mix by spoonfuls on top of stew, cover and continue to simmer for another 20-25 minutes or until toothpick comes out clean from center of the dumplings.