Just a few additional ingredients are needed bring these thick slices of tomatoes to a new level.
3 tablespoons minced shallots
3 tablespoons red wine vinegar
1/2 teaspoon kosher salt plus more
1/2 teaspoon sugar
1/2 cup extra-virgin olive oil
5 large ripe beefsteak or heirloom tomatoes, cut into 1/2" slices
Freshly ground black pepper
1/2 teaspoon dried oregano
10 fresh medium basil leaves, torn into approx. 1/2" pieces
Combine shallots, vinegar, 1/2 teaspoon salt, and sugar in a small bowl. Gradually whisk in oil to blend. Set vinaigrette aside.
Arrange tomatoes on a large platter. Season with salt and pepper and dried oregano.