Bring a large pot of salted water to a boil. Add 8 ounces of spaghetti or your pasta of choice and cook according to package instructions until al dente. Reserve about 1/4 cup of pasta water before draining to help loosen the sauce later if needed.

While the pasta cooks, heat 2 tablespoons of olive oil in a large skillet over medium-high heat. Add 4 cloves of minced garlic and sauté for about 30 seconds until fragrant, careful not to burn it. Add 1 pound of sliced chicken breast, sprinkle with 1 teaspoon salt and 1/2 teaspoon black pepper, and cook for 5-7 minutes, stirring occasionally until the chicken is cooked through and golden.

Reduce heat to medium. Stir in the zest and juice of 1 lemon, 1/4 cup chicken broth, and 1 teaspoon red pepper flakes if using. Let it simmer for 2 minutes, allowing the flavors to meld and the sauce to slightly reduce.

Add the drained pasta directly into the skillet with the chicken and lemon sauce. Toss everything together, adding a splash of reserved pasta water if the mixture seems dry. Stir in 1/4 cup chopped fresh parsley for a burst of color and freshness.

Divide the pasta among plates or bowls. Generously sprinkle with grated Parmesan cheese and an extra squeeze of lemon if desired. Serve immediately and enjoy your quick, vibrant meal!