Boil the pasta. Bring a large pot of salted water to a rolling boil. Cook the pasta until al dente according to package instructions. Reserve 1 cup of pasta water before draining.

Prep the chicken. Pat the chicken dry and season generously with salt and pepper. If you like a little heat, add a pinch of red pepper flakes.

Cook the chicken. Heat olive oil in a large skillet over medium-high. Add chicken in a single layer and let it sear until golden, 3–4 minutes per side, depending on size. Don’t crowd the pan. If needed, cook in batches. Remove to a plate.

Optional aromatics. Reduce heat to medium. Add minced garlic to the same pan and cook for 30 seconds until fragrant. Don’t let it burn.

Build the sauce. Add 1/2 cup of the reserved pasta water to the skillet. Stir in the pesto and a squeeze of lemon juice. If using cream, add it now. Simmer gently for 1 minute to combine. The sauce should be glossy and loosened, not thick and clumpy.

Add pasta and chicken. Toss the drained pasta and cooked chicken into the skillet. Add a splash more pasta water as needed to help the sauce coat everything.

Finish with cheese and zest. Stir in the Parmesan and a little lemon zest. Taste and adjust with salt, pepper, or more lemon.

Optional add-ins. Fold in spinach (it will wilt quickly) and cherry tomatoes at the end for color and freshness.

Serve hot. Top with extra Parmesan and a drizzle of olive oil. Serve immediately while it’s saucy and vibrant.