Peel and finely slice the eschalots and place in a small non-metallic bowl with two good splashes of red wine vinegar, caster sugar and salt to taste.
Stir to combine and leave for at least 30mins to soften. Slice and chop the heirloom tomatoes haphazardly. No need to be uniform, they’re nice if some are larger pieces and you can even keep some of the little ones whole.
Tear the mozzarella into small pieces and mix with the tomatoes gently along with most of the basil leaves
Drain the eschalots, reserving remaining vinegar and add to the salad.
Divide salad among 5 plates, garnish with extra basil sprigs and drizzle with vinegar and olive oil to taste.
Serve with a good sprinkling of cracked black pepper.