01 - Cook pasta in a large pot of salted boiling water according to package directions until al dente. Reserve 1/2 cup pasta water before draining.
02 - Heat olive oil in a large skillet over medium-high heat. Season chicken pieces with salt and pepper, then sauté until golden and cooked through, 6-8 minutes. Transfer to plate and set aside.
03 - Reduce heat to medium, add butter to the same skillet. Sauté garlic for 1 minute until fragrant.
04 - Pour in heavy cream and bring to gentle simmer. Stir in pesto and Parmesan cheese, mixing until cheese melts and sauce is smooth.
05 - Return chicken to skillet. Add drained pasta and cherry tomatoes. Toss to coat everything in creamy pesto sauce. Add reserved pasta water as needed for desired consistency.
06 - Taste and adjust seasoning with salt and pepper. Serve immediately, garnished with extra Parmesan and fresh basil if desired.