Saute shallots in 1 tablespoon butter in a small skillet until tender. Add broth; bring to a boil. Reduce heat; simmer until liquid is reduced to about 1 tablespoon. Stir in vinegar and Worcestershire sauce; cook 1 minute longer. Remove from the heat. Stir in 1-1/2 teaspoons butter. Cover and keep warm., Sprinkle steaks with pepper. In a large skillet, cook steaks in oil and remaining butter until meat reaches desired doneness (for medium-rare, a thermometer should read 135°; medium, 140°; medium-well, 145°). Serve with shallot sauce.