Preheat the griddle to high heat and place the cast iron skillet on top; let it heat for about 5 minutes.
Season the chicken thighs with salt, 1 teaspoon of pepper, and Tuscan Herb seasoning.
On the other side of the griddle set to medium-high, add a drizzle of avocado oil and sear the chicken for about 5 minutes per side, or until fully cooked.
While the chicken cooks, add butter, shallots, and garlic to the heated skillet and sauté until the shallots are translucent and fragrant.
Stir in the coconut milk and almond milk, then season with the remaining 1 teaspoon of pepper. Gradually add the grated Parmesan cheese, stirring until fully melted and incorporated.
In a small cup, mix the arrowroot powder (or cornstarch) with water. Slowly whisk the slurry into the sauce and stir until it thickens to your desired consistency.
Remove the cooked chicken from the griddle and slice it into strips.
Add the al dente fettuccine noodles to the sauce and stir to coat. Let the noodles simmer in the sauce for 1–2 minutes.
Add the sliced chicken to the skillet, sprinkle with shredded Parmesan cheese, and garnish with chopped parsley.
