Wash and core the tomato and slice off both the stem end and the bottom of the tomato and discard. Slice the remaining tomato into about 5 or 6 slices.
You want a basil leaf for each piece of the tomato slice. Slice the mozzarella cheese into about 5 or 6 slices as well. If you have some left over, that is ok. Lay each tomato slice on the plate, sprinkle tomatoes with a bit of kosher salt. Then top each tomato slice with a basil leaf, and then top with a slice of mozzarella.
Mix together the olive oil and balsamic vinegar, and drizzle over the salad. Serve immediately. This salad does not make hold well the next day, the basil leaves wilt. Yield: 1 large serving