1. Combine first 6 ingredients in a saucepan over medium-high heat. Add chicken to pan; bring mixture to a boil. Reduce heat, and simmer 14 minutes or until chicken is done. Remove chicken, reserving cooking liquid; cool. Shred chicken. Strain cooking liquid through a fine sieve over a bowl; discard solids.
2. Wipe pan with paper towels. Sauté sausage over medium-high heat 2 minutes. Add potato, onion, and bell pepper; sauté 8 minutes, stirring occasionally. Add garlic and next 3 ingredients (through saffron); sauté 2 minutes, stirring constantly. Add reserved cooking liquid; bring to a simmer. Simmer 12 minutes, stirring occasionally. Add shredded chicken; simmer 5 minutes. Remove from heat; stir in vinegar. Ladle about 1 cup stew into each of 4 bowls; top each serving with parsley.