Combine ½ teaspoon Italian seasoning, salt, pepper, 2 tablespoons shredded parmesan, and flour. Coat chicken tenderloins in this mixture. Or sprinkle the seasonings all over the chicken.
In a large Dutch oven or a deep skillet that has a lid, melt 1 tablespoon butter and add 1 teaspoon oil. Cook the chicken until fully done. Remove chicken, set aside on a plate, and keep warm.
In the same pot, using the remaining oil/butter, cook onion until soft and translucent (for 2 minutes). Add garlic and cook for an additional minute or until fragrant.
Deglaze the pot with ½ cup chicken stock, then add the remaining stock and half and half.
Add pasta to the pot, stirring well to coat it in the liquid. Bring to a boil, then reduce heat, cover, and simmer for 11-13 minutes, stirring intermittently, until pasta is al dente.
The sauce will be thin initially. Add the remaining Italian seasoning and ¾ cup shredded parmesan cheese. Stir well. The sauce will thicken as it cools.
Taste and adjust with salt and pepper if needed. Return the cooked chicken to the pot. You can either top the pasta with the chicken or mix it in.