Bring a large pot of salted water to a boil over high heat. Add the penne pasta and cook according to package instructions until just shy of al dente, about 8–10 minutes. Reserve about 1 cup of starchy water before draining the pasta in a colander.

In a large skillet, heat 2 tablespoons of olive oil over medium heat. Add the diced yellow onion and sauté for about 5 minutes until it becomes translucent and fragrant.

Add 1 pound of ground turkey to the skillet, breaking it apart as it cooks. Season with salt, black pepper, and Italian seasoning. Cook for 6–8 minutes until browned, then add minced garlic and stir for 1 minute.

Sprinkle 2 tablespoons of all-purpose flour over the turkey mixture and stir to combine, cooking for about 1 minute. Slowly pour in 1 cup of chicken broth and 1 cup of tomato sauce, mixing well. Allow the sauce to simmer for 3–5 minutes until it thickens.

Gently fold the drained penne pasta into the sauce mixture. Pour in 1 cup of half-and-half and stir to combine, adjusting the thickness with reserved pasta water if needed.

Stir in half of the shredded mozzarella and cheddar cheese, mixing until melted. Sprinkle remaining cheese on top and cover the skillet, allowing the heat to melt the cheese further.

Once the cheese is melted, remove from heat and garnish with chopped fresh parsley and a sprinkle of red chili flakes. Serve warm.