Slice tomatoes into 1/4-inch rounds and divide among 4 plates. Place 1 basil leaf atop each piece of tomato.
Sprinkle tomatoes and basil with 1 1/2 tablespoon of vinegar per plate.
Slice avocado into 1/4-inch slices and place slices on top of each tomato round.
Sprinkle all with salt and pepper. Enjoy immediately.

2 large red or yellow tomatoes (heirloom varieties if available)
1 large avocado, ripe but not too soft
20 large basil leaves
6 tablespoon balsamic vinegar (dark for red tomatoes, white for yellow ones)
freshly milled coarse sea salt and black pepper to taste