Remove skin from chicken and discard. Season chicken with salt.
Heat 1 tablespoon of the oil in a large, deep covered saute pan over medium-high heat. Add chicken and brown, meaty-side down, 3 minutes. Turn chicken over and continue to cook 1 minute. Remove to plate.
Reduce heat to medium. Add remaining tablespoon oil to pan and add mushrooms, green peppers and onion. Cook, stirring occasionally, 5 minutes until softened. Add garlic and cook 1 more minute. Stir in tomatoes, wine or water, rosemary and red pepper flakes. Bring to a simmer. Add chicken, cover and simmer 15 minutes. Uncover and continue to cook 10 minutes, until chicken is cooked through and tender. Serve over whole-wheat spaghetti.