Place balsamic vinegar in a 1 quart saucepan and simmer over medium heat, stirring often until reduced by about ⅔ (about 15 minutes)
While vinegar simmers, heat grill to medium heat. Season steak with pepper and grill to desired doneness. Add salt as desired. Transfer to board to rest.
While steak rests, arrange lettuce, tomatoes and cheese slices.
Cut steak into strips and arrange on the plate.
Drizzle with oil then top with balsamic reduction.
Recipe by Cindy's Recipes and Writings at https://www.cindysrecipesandwritings.com/steak-caprese-salad-weekdaysupper/