For the Bruschetta Grilled Chicken:

1. Add thinly sliced chicken breasts to a bowl or plastic bag, then add in the pesto, lemon juice, salt, and pepper. Mix until well combined and the chicken is fully coated in the pesto mixture. Set aside to marinate for 15-20 minutes while you work on the bruschetta.
2. Slice the tomato into a ¼” dice (or slice in half if using cherry tomatoes). Add to a bowl with basil, garlic, olive oil, balsamic vinegar, and a pinch of salt. Mix to combine, then set aside. 
3. Now cook the chicken.
   1. For the Grill: Preheat your grill to medium-high heat (about 400–450°F). Lightly oil the grates, then add the marinated chicken. Grill for 2–3 minutes per side, or until the chicken reaches an internal temperature of 165°F. During the last minute of cooking, top each piece with mozzarella and parmesan and close the grill lid to allow the cheese to melt.
   2. For Stovetop: Heat a large oven-safe skillet over medium-high heat and lightly coat with olive oil. Once hot, add the marinated chicken in a single layer, working in batches if needed to avoid overcrowding the pan. Cook for 2–3 minutes per side, or until the chicken reaches an internal temperature of 165°F. Top each piece with mozzarella and parmesan, then transfer the skillet to the oven and broil for 1–2 minutes, watching closely, until the cheese is melted and golden brown in spots. You can also transfer to a baking sheet if you don’t have an oven-safe skillet.
4. Transfer the chicken to a serving plate to rest for 5 minutes, then top with the bruschetta. Garnish with extra basil and parmesan cheese and serve immediately.