In a shallow bowl, stir together the flour, cornflour, onion powder, garlic powder, salt, black pepper and cayenne pepper until thoroughly mixed. Remove 1/3 cup of the flour mixture and set aside. Gently press the steaks into the remaining flour mixture in the bowl until well coated on both sides.
Heat butter and olive oil in a large frypan over medium heat until the foam subsides on the butter. Gently pan-fry the steaks until the coating is browned; about 4 minutes per side. Turn only once. Remove the steaks to a platter.
Spread the onions out into the frypan with the remaining oil and butter then cook over medium heat until the onions are translucent; 5 to 7 minutes stirring often. Sprinkle the reserved flour mixture over the onions; cook and stir for 1 more minute then pour in the beef stock and milk.
Bring the mixture to a boil stirring constantly until the gravy is thickened. Scrape the frypan well to dissolve any flavour bits left in the bottom.
Return the browned steaks to the gravy mixture then push them down into the gravy. Cover the frypan, reduce heat to low and simmer until the steaks are very tender; about 45 minutes stirring occasionally.
Hi Gennie, the gram weight differs for a cup depending on what you are measuring. For example, one cup of white sugar weighs 220g but one cup of flour is only 125g, because flour is lighter. - 25 Feb 2013