Marinate the chicken in a bowl, combine pesto, olive oil, lemon juice, salt, and pepper. Add the chicken and toss until coated. Cover and refrigerate for at least 30 minutes, or up to 4 hours.
Grill over medium heat for about 3 minutes per side, or until the chicken reaches 165°F. You can also cook it in a grill pan or skillet.
Let the chicken cool, then refrigerate until chilled.
Assemble the Skewers
Thread each skewer with one piece of pesto chicken, one cherry tomato, and a folded basil leaf. Add mozzarella then repeat.
Notes
Make-ahead tipYou can cook the chicken the day before and assemble the skewers the morning of your event. Keep them covered and refrigerated until serving.