Bring a large sauce pot of water to a boil. Add the pasta and cook according to package directions, about 7 to 8 minutes for al dente pasta. Reserve 1 cup of pasta water before draining. Lightly drizzle cooked pasta with olive oil and cover to keep warm. Set aside.
While the water boils, thinly slice/cube the chicken and season the slices with ½ teaspoon sea salt, ¼ teaspoon black pepper, and 1 teaspoon Italian seasoning.
Heat ½ tablespoon of the avocado oil over medium-high heat in a large, nonstick pan. Add half of the chicken slices in a single layer in the pan. Cook undisturbed on one side, for 2 to 3 minutes, or until browned. Turn the chicken over and cook another 2 to 3 minutes, or until browned. Remove the chicken from the pan and tent with foil to keep warm. Add the remaining ½ tablespoon of oil and repeat the process with the second half of the chicken.
Carefully wipe the pan out with paper towel. Reduce heat to medium-low heat. Add the remaining ½ Tbsp of olive oil. Add the onion, garlic, and sundried tomatoes and saute for 2 to 3 minutes, or until lightly fragrant.
Deglaze the pan with the white wine. Stir in the tomato paste.
Whisk together the milk and flour to create a slurry. Add the slurry to the pan, mixing to incorporate. Season the sauce with remaining ½ teaspoon of sea salt, ¼ teaspoon of pepper, and 1 teaspoon of Italian seasoning. Cook for 3 to 4 minutes, or until the liquid thickens. If the sauce is too thick, you can thin it down with the reserved pasta water/broth to the desired consistency.
Add the kale to the sauce and cook for 1 to 2 minutes, or until slightly wilted.
Pour the sauce over the prepared pasta. Divide the sundried pasta among plates and top with cooked chicken. Garnish with Parmesan cheese, if desired.