1/2 C. chopped sweet onion
3 tsp. olive oil, divided
6-1/2 C. fresh baby spinach chopped
1 garlic clove, minced
1 Tbsp. balsamic vinegar
1/4 C. crumbled feta cheese
1/2 tsp. grated lemon peel
1/4 tsp. salt
1/4 tsp pepper
4 boneless, skinless chicken breast halves (6 oz each)
1. In a large skillet, cook onion in 2 tsp. oil over medium heat for 15-20 minutes or until onion is golden brown, stirring frequently. Add the spinach, garlic and vinegar; cook 1 minute longer. Remove from heat; cool for 5 minutes. Stir in the cheese, lemon peel, salt and pepper.
2. Flatten chicken to 1/4-in thickness. Spread spinach mixture over chicken. Roll up and secure with toothpicks.
3. In large skillet over medium heat, cook chicken in remaining oil for 8-10 minutes on each side or until chicken juices run clear. Discard toothpicks.