Melt butter in sauté pan. Add garlic and cook for 2 minutes. Sprinkle chicken with salt and pepper and dredge in flour. Sauté chicken in pan until browned. Remove chicken from pan and set aside. Add artichokes and sun dried tomatoes to sauté pan, using some of the oil from the jar. Scrap up browned bits from pan and stir until mixture thickens slightly. Add chicken broth to pan and simmer for several minutes. It thicker sauce is desired add the cornstarch dissolved in cold water. Return chicken to pan and cover. Simmer about 30 minutes until chicken is cooked.