1 pint mixed cherry tomatoes, preferably heirloom, halved
7 tablespoons (or more) extra-virgin olive oil, divided
Flaky sea salt
2 pounds mixed medium and large tomatoes, preferably heirloom, cut into thin slices and/or wedges
8 ounces buffalo mozzarella or mozzarella, room temperature, torn into pieces
Coarsely ground black pepper
Small basil leaves and toasted country bread (for serving)
Toss cherry tomatoes with 1 Tbsp. oil in a small bowl; season with salt.
Arrange tomato slices on a platter, slightly overlapping; season generously with salt. Arrange mozzarella over tomatoes; lightly season mozzarella with salt. Spoon cherry tomatoes over salad and drizzle with 6 Tbsp. oil; season with pepper. Let stand 30 minutes to let flavors meld and release juices from tomatoes and mozzarella.
Top salad with basil and additional salt and oil, if desired.