Heat oven to 350 degrees. Melt 2 tablespoons butter in baking pan. Add breasts and bake for 30 minutes. Melt remaining butter in saucepan; add flour and cook briefly, stirring. Add broth and wine, stirring constantly until sauce is thick and smooth.
Remove chicken from oven; turn and cover each with mushrooms, green onion, and artichokes. Pour sauce over all and bake for 30 minutes or until tender.