In a 5-1/2- or 6-quart slow cooker, combine mushrooms and pearl onions. Stir in the 1/2 cup broth, the wine, tomato paste, garlic salt, rosemary, thyme, pepper, and bay leaf. Add chicken legs to cooker.

Cover and cook on low-heat setting for 7 to 8 hours or on high-heat setting for 3-1/2 to 4 hours.

Using a slotted spoon, transfer chicken and vegetables to a serving platter. Discard bay leaf. Cover chicken and vegetables and keep warm.

For sauce: Skim fat from cooking liquid. Measure 2 cups of the cooking liquid, adding additional chicken broth, if necessary, to equal 2 cups total liquid. Transfer liquid to a medium saucepan. In a small bowl, stir the 1/4 cup broth into the flour; stir into liquid in saucepan. Cook and stir until thickened and bubbly; cook and stir for 1 minute more. Spoon some of the sauce over chicken. Pass remaining sauce. If desired, serve with mashed potatoes and garnish with parsley. Makes 4 servings.