Place all halved tomatoes in a colander set over a mixing bowl. Season generously with flaky sea salt. Allow to sit. Reserve the tomato liquid for another use, then transfer the seasoned tomatoes to a large mixing bowl.
In a large bowl, whisk together olive oil, aged balsamic vinegar, dried oregano, black pepper, and a pinch of crushed red pepper flakes.
To the dressing, add the seasoned tomatoes, sliced cloves of garlic, and sliced basil. If using cheese, add that now. Gently toss to combine, then transfer to a bowl or serving plate. Sprinkle with additional flaky sea salt to taste. Can be enjoyed as a salad or served over toasted baguette as crostini.