Add the finely minced shallot, sliced basil, 2 tablespoons olive oil, 1 tablespoon red wine vinegar, and 1 teaspoon honey (or sugar) to the tomatoes. Stir gently to combine.

Season the relish with 1 teaspoon salt and 1/2 teaspoon freshly ground black pepper. Taste and adjust acidity or sweetness as needed (add an extra 1/2 teaspoon vinegar or 1/2 teaspoon honey if desired). Let the relish sit at room temperature for 10–15 minutes to meld flavors.

Prepare greens and cheese

While the relish rests, rinse the mesclun mix and romaine hearts in cold water. Spin or pat dry thoroughly. Place 4 cups mesclun and 2 cups chopped romaine into a large salad bowl and gently toss to combine.

Tear or halve the fresh mozzarella into bite-sized pieces (approximately 8 oz total). Scatter the mozzarella over the mixed greens, reserving a few pieces to place on top for presentation.

Assemble salad

Spoon the tomato relish evenly over the salad greens and mozzarella. Drizzle the reserved 1 teaspoon olive oil and optional 1/2 teaspoon lemon juice over the top for added brightness.

Gently toss the salad 2–3 times to distribute the relish and cheese without bruising the mesclun. Taste and adjust seasoning: sprinkle the optional 1/4 teaspoon coarse sea salt and a light grind of black pepper if needed.

Transfer the salad to individual plates or a large serving bowl. Garnish with any remaining basil or a light additional drizzle of olive oil, then serve immediately.