Cut chicken into bite-size chunks. Season with salt, pepper, and Italian seasoning.
1 pound boneless, skinless chicken breasts, ½ teaspoon kosher salt, ¼ teaspoon freshly ground black pepper, 1 teaspoon Italian seasoning
Heat olive oil in a large pan over medium-high heat. Add the seasoned chicken and cook for 2-3 minutes without turning so a golden brown crust can develop on the bottom side. Flip the chicken pieces to cook for another 2-3 minutes on the other side until cooked through. Transfer the cooked chicken to a plate and set aside.
2 tablespoons olive oil
Add the butter to the pan and stir to scrape up any browned bits. Add garlic and onion and sauté for 30-60 seconds.
2 tablespoons salted butter, 4 cloves garlic, ½ onion
Sprinkle the flour over the butter, onion, and garlic. Cook and stir for 1-2 minutes. Add chicken broth, half-and-half, and red pepper flakes while stirring. Bring to a simmer, then reduce heat and cook on medium-low for 5 minutes. Reduce heat to low and stir in grated Parmesan cheese and lemon juice.
2 tablespoons all-purpose flour, 1 cup chicken broth, ½ cup heavy cream, ¼ teaspoon red pepper flakes, ½ cup freshly grated Parmesan cheese, 2 teaspoons freshly squeezed lemon juice
Meanwhile, bring a large pot of water to a boil. Add 1 Tablespoon kosher salt along with the pasta. Cook according to the package instructions until al dente. Add broccoli during the last 2-3 minutes. Remove 1 cup of the pasta water and set aside. Drain remaining pasta water.
8-12 ounces dried penne pasta, 3 cups broccoli florets
Combine cooked pasta and broccoli, cooked chicken, toasted pine nuts (if using) and sauce. Toss to evenly coat. Add additional pasta water if needed to get the consistency you like, then taste and adjust seasonings as needed. Serve with additional Parmesan cheese grated on top.
⅓ cup toasted pine nuts