Saute the
sliced onions and sugar in a large skillet over high heat, stirring
occasionally, for about 10 minutes, until the juices from the
onions have evaporated. Reduce heat to medium and cook, stirring
constantly, until the onions are golden brown. Add the vinegar,
crushed red pepper flakes, lemon juice and salt and pepper to
taste and set aside until ready to serve.
Meanwhile,
preheat your grill or broiler. Rub the steak with the seasonings
and grill over medium-high heat for 5 to 7 minutes per side. Or,
broil in the oven 6 inches from the heat about the same amount
of time.