Adapted from the Cooking Pleasures magazine. This is a quick-cooking saute making it ideal for a weekday meal. Also, uses 1 skillet so clean-up is a breeze. The simple glaze is reduced to give the dish a sweet-sour taste.
Sprinkle both sides of chicken with 1/4 teaspoons of the salt and pepper. Heat oil in a large skillet over medium-high heat until hot. Add chicken; cook 4 to 6 minutes or until brown, turning once. Cover and reduce heat to medium; cook 4 minutes or until chicken is no longer pink in center and juices run clear. Place on plate; loosely cover to keep warm.
Increase heat to medium-high. To same skillet, add bell pepper, onion and garlic. Cook 1 to 2 minutes or until vegetables just begin to soften. Add spinach; sprinkle with remaining 1/8 teaspoons salt. Remove from heat; toss until spinach is barely wilted. Place on serving plates or platter. Top with chicken.
Return same skillet to high heat. Add vinegar and brown sugar. Bring to a boil; boil 30 to 60 seconds or until slightly thickened, scraping up browned bits from bottom of skillet. Drizzle balsamic glaze around chicken and vegetables.