Heat oil in large skillet over medium-high heat until hot. Add lemon juice and steaks; cook 8 to 10 minutes or until of desired doneness, turning once. Remove steaks from skillet; cover to keep warm.
Add onions and wine to juice mixture in skillet; cook and stir 4 minutes or until liquid is reduced to about 1/2 cup.
To serve, spoon onion mixture over steaks; sprinkle with parsley.