Boil water in medium pot. When boiling cook Cipollini onions for one minute then drain water. When Cipollini onions are cool peel off the skins. Leave onions whole.
In a large pot (like Le Creuset) sauté onion and garlic in olive oil until translucent and fragrant.
Add in mushrooms and season with salt, pepper, and 21 spice mixture.
Add half the beer to loosen bits at the bottom of the pot. Cook a few minutes to cook off the alcohol.
Add vegetables (Cipollini onions, carrots, and potatoes). Sauté a few minutes then add the rest of the beer. Cook a few minutes longer, then add vegetable broth.
Add tomato paste.
Prepare and add arrowroot mixture to the stew.
Cook on low for three to four hours. The longer the stew cooks, the better the flavors marry.
Serve hot with warm, crusty bread (mine was gluten-free).