Bring a large pot of salted water to a boil and cook the penne according to package directions until al dente; drain and set aside.
Meanwhile, heat 2 tsp olive oil in a large skillet over medium heat.
Season both sides of the chicken breasts with a pinch of salt and pepper, then cook in the skillet 3–4 minutes per side, or until cooked through; transfer to a plate.
Spread 1 tsp prepared basil pesto over each cooked chicken breast and tent loosely with foil to keep warm.
In the same skillet, add the butter and garlic and cook briefly, scraping up any browned bits.
Add the cream cheese and whisk until mostly melted, then reduce heat to medium-low.
Slowly whisk in the heavy cream until smooth, then stir in the grated Parmesan, 1/4 tsp salt, 1/4 tsp pepper, and the drained sun-dried tomatoes; cook until sauce is smooth and heated through.
Add the drained penne directly to the skillet and toss to coat evenly with the Alfredo sauce.
Serve the sauced penne with the pesto-topped chicken breasts alongside and enjoy immediately.