1.
To make the dressing, place the yogurt, vinegar, lemon juice, maple syrup, mustard and basil in a bowl and whisk until smooth. Season with a pinch of salt and plenty of pepper.
2.
To serve, tear the lettuce leaves into bite-sized pieces and place in a large bowl. Add enough of the dressing to just coat (not drown) the leaves, then fold in the Parmesan. Toss to combine, then transfer to wide-rimmed serving bowls, scatter over the cherry tomatoes, chicken and sunflower seeds. Garnish with a little extra Parmesan.