In shallow dish, combine 4 tablespoons flour and black pepper. Dredge chicken breast halves in mixture.

In large skillet over high heat, melt cup butter (1/2 stick). Add green onions; saut over medium heat until softened, about 2 minutes. Add chicken to pan; cook, turning once, until lightly golden brown on both sides, about 3 to 4 minutes per side. Remove chicken from pan and keep warm.

Add chicken stock and wine to pan, stirring to scrape bits off bottom. Bring mixture to a boil and cook until reduced by half, about 6 minutes.

In small bowl, knead together remaining 2 tablespoons of flour and cup butter. Whisk into sauce and stir until thickened. Stir in lemon juice and artichoke hearts. Stir in salt.

Add chicken and cook, covered, until heated through, about 7 minutes. Just before serving, add capers and chopped parsley to chicken.