Start by bringing a large pot of salted water to a boil. You’ll want to use about 1 tablespoon of salt for every 12 cups of water. This helps season the penne pasta as it cooks. Once it comes to a rolling boil, add the penne pasta and cook according to package instructions, but remember to reduce the cooking time by one minute for a perfect al dente texture.
After cooking, drain the penne pasta and set it aside. Keep an eye on it while you prepare the sauce to prevent it from becoming mushy.
In a large pan, heat over medium heat and add 1 tablespoon of oil from the sun-dried tomatoes. Once the oil heats up, toss in the sliced mushrooms. Cook them for about 3 minutes, stirring occasionally, until they become tender and slightly golden.
Next, add the chopped sun-dried tomatoes to the pan and let everything cook together for another 1 to 2 minutes. The flavors will deepen, making your kitchen smell divine. Once done, remove the mushroom-tomato mixture from the pan and set it aside on a plate.
Increase the heat to medium-high and add another tablespoon of sundried tomato oil along with the unsalted butter. Allow the butter to melt completely. As it melts, add the minced garlic and sauté until fragrant, which should take about 30 seconds.
Sprinkle the flour over the mixture while whisking continuously for about a minute. This helps prevent any lumps from forming and creates a smooth base for your sauce.
Gradually pour in the chicken stock, whisking to combine, and then follow with the milk. Keep whisking as you bring the mixture to a boil, then reduce the heat to medium-low. Let it simmer gently until the sauce thickens, stirring occasionally to prevent sticking.
Once the sauce reaches a nice consistency, reduce the heat to low. Stir in the Italian seasoning and 5 tablespoons of Parmesan cheese. Take a moment to season with salt and pepper to taste; I usually add about 1/2 teaspoon of salt and 1/4 teaspoon of pepper for a balanced flavor.
Now it’s time to bring everything together! Add the cooked penne pasta, the sautéed mushrooms, chicken, and the packed spinach back into the pan. Toss everything together to ensure each piece is coated in that glorious sauce. Allow the spinach to wilt, which should take about 1 to 3 minutes over medium heat.
Finally, remove the pan from the heat and sprinkle an additional 1/2 cup of Parmesan cheese over everything for a cheesy finish. Give it a final stir to combine and serve immediately, garnishing with fresh thyme if desired. Enjoy!
