Trim all the visible fat from the steak.
Mix together the soy sauce, oil, brown sugar, onion, garlic, ginger root and hot pepper sauce, stirring until sugar is dissolved.
Pour over the beer. (Don't use flat beer, it should be fresh and bubbly.)
Place the steak in a gallon size heavy duty plastic bag with a zip top. (Or double two regular plastic bags.) Pour over the marinade. Seal and turn the bag several times to evenly coat the meat with the marinade.
Place in the refrigerator for 24 hours.
Remove the steak from the marinade. (Discard marinade.)
Place the steak on a hot grill. Grill to desired doneness, turning only once.
Place steak on a cutting board. Slice on the diagonal, across the grain, into very thin slices. Serve immediately.
Slicing across the grain is very important for flank and brisket cuts of beef. Slicing with the grain makes the meat texture tough and difficult to chew.