Sea salt and freshly ground black pepper, to taste
Fresh basil leaves
To grill the chicken
Lightly oil a grill set to medium-high heat. Season the chicken breasts with sea salt and freshly ground black pepper. Grill until done, 8 to 10 minutes, turning the chicken breasts halfway through. Let cool, then slice.
To assemble the salad
In a small bowl, combine the pesto, olive oil, and lemon juice. The dressing should be thick but pourable. Add more olive oil, if necessary.
Spread the arugula over a large serving plate. Add the cherry tomatoes, then the sliced grilled chicken. Pour the pesto dressing over the chicken. Break the balls of Mozzarina di Bufala cheese into large pieces, then set over the salad. Season with sea salt and black pepper, to taste. Garnish with fresh basil leaves and serve immediately.