Combine the flour, ½ teaspoon of Italian seasoning, salt, pepper, and 2 tablespoons of shredded parmesan in a small bowl. Coat the chicken tenderloins evenly in this mixture. Alternatively, sprinkle the seasonings directly onto the chicken.
In a large Dutch oven or a deep skillet with a lid, heat 1 teaspoon of olive oil with 1 tablespoon of butter. Cook the chicken until thoroughly cooked, then remove it and set aside, keeping it warm.
Using the remaining butter and oil in the same pot, sauté the onion until it becomes soft and translucent, about 2 minutes. Add minced garlic and cook for 1 minute until fragrant.
Deglaze the pot with ½ cup of chicken stock, scraping up any browned bits from the bottom. Pour in the rest of the chicken stock along with the half and half.
Add the pasta, stirring to coat it evenly in the liquid. Bring to a boil, then reduce the heat to a simmer. Cover with a lid and let the pasta cook for 11-13 minutes, stirring occasionally, until it reaches an al dente texture.
As the sauce will initially be thin, add the remaining ¾ cup of shredded parmesan cheese and the remaining Italian seasoning. Stir thoroughly to combine. The sauce will thicken as it cools slightly.
Season the sauce to taste with additional salt and pepper if needed. Return the chicken to the pot, placing it on top of the pasta or mixing it in.