Pat the legs dry and season on both sides with salt and pepper. Dust both sides with flour.
In a sauté pan, melt the butter over medium heat until it begins to bubble. Add the legs, skin side down and cook until golden brown, about 4 minutes. Turn over for about 1 minute, then remove the meat to a platter.
In the same pan, add the onions and cabbage and sauté until soft and brown, about 5 minutes.
Add the grapes and stir. Add the legs, brown side up and nestle them into the cabbage and onions.
Add the brandy and light with a match. Let the alcohol burn off and reduce.
Add the stock and cover partially with a lid and cook at a low simmer for about 1 hour, until the meat falls off the bone.
Finish with lemon juice and parsley and more salt and pepper to taste.