6 bone-in chicken thighs, skin removed, trimmed of fat
2 pounds sweet potatoes, peeled and cut into spears
1/2 pound white button mushrooms, thinly sliced
6 large shallots, peeled and halved
4 cloves garlic, peeled
1 cup dry white wine
2 teaspoons chopped fresh rosemary, or 1/2 teaspoon dried rosemary, crushed
1 teaspoon salt
1/2 teaspoon freshly ground pepper
1 1/2 tablespoons white-wine vinegar