Cut bacon into thin strips and cook in 6-qt pot over low heat until golden brown, about 5 min, stirring constantly.
Remove from pot with a slotted spoon and set aside.
Add a little less than half the butter to the pot and cook the onions over very low heat until golden, turning frequently, about 10 min.
Remove with slotted spoon and add to the bacon.
Cut the meat into 2" cubes.
Cook in the pot in batches until lightly browned, about 5 min, turning frequently. Set aside.
Discard the fat from the pot.
Add the brandy and, 1 min later, the wine, scraping up browned bits with a wooden spoon.
Return the meat to the pot and bring to simmer, Cover and cook over very low heat for 3 hrs.
Meanwhile, trim the mushroom stems, rinse the mushrooms and pat dry.
Melt the remaining butter in a nonstick 10" sauté pan.
Add the mushrooms and lemon juice, season with salt and pepper, and cook the mushrooms until they are golden and have stopped giving out any liquid.
Add the bacon, onions and mushrooms to the pot and cook over low heat, covered, for 1 hr longer.
Remove the meat and vegetables with a slotted spoon and set aside.
Bring the sauce to boil.
Blend the arrowroot and cold water, add to the boiling sauce and boil over high heat for 1 1/2 min or until the sauce is thickened and smooth.
Return the meat and vegetables to the pot and reheat for 2 min.
Transfer to a shallow dish and serve.