zuesel

See somewhereintime's pro way above.

My lazy way is easy.

Make gravy using the sauce remaining from frying the steak (add water and butter)
Add chopped garlic
(optional: add a bit of red wine) bring to boil
Turn heat to medium, add flour while whisking the sauce very fast.
(Some chinese places use corn starch solution (cornstarch+water mix) instead of flour. But it turns watery after awhile and doesn't taste very good)
Add salt to taste, dark soy sauce for color.