In shallow dish, place 1/2 cup Bisquick mix. Into small bowl, pour buttermilk. In another shallow dish, place bread crumbs. Coat beef steaks with Bisquick mix. Dip each coated steak into buttermilk, then coat with bread crumbs.
In 12-inch nonstick skillet, heat oil over medium-high heat. Add steaks; cook 6 to 8 minutes, turning once, until thoroughly cooked. Remove from skillet; cover with foil to keep warm.
In same skillet, cook onions over medium heat 5 to 7 minutes, stirring occasionally, until tender.
In tightly covered container, shake 3 tablespoons Bisquick mix and the half-and-half until blended. Pour into onions in skillet. Cook over low heat 2 to 3 minutes, stirring occasionally, until gravy is thickened. Pour gravy over steaks; sprinkle with parsley.