Start by slicing the heirloom tomatoes into thick rounds to showcase their vibrant colors and juicy interior.
Next, peel the cucumber and slice it into thin rounds, adding a crisp texture to the salad.
Slice the fresh mozzarella into even rounds or tear it into bite-sized pieces for a creamy, silky contrast.
Place all the sliced tomatoes, cucumbers, and mozzarella in a large mixing bowl.
Rip or tear the basil leaves into smaller pieces and scatter them over the salad for fragrant freshness.
Drizzle the olive oil evenly over the ingredients, then add balsamic vinegar if using, for a touch of sweetness and acidity.
Sprinkle with sea salt and freshly ground black pepper to enhance all the flavors, then gently toss everything together until well combined.
Hold the bowl and shake gently, or use a spoon to fold ingredients carefully, ensuring each piece gets coated with the dressing.
Serve the salad immediately on chilled plates to preserve the bright colors and fresh textures.