Preheat oven to 350 degrees F (175 degrees C).
In a large, ovenproof skillet with deep sides, heat Olive Oil (1 dash) over medium-high heat.
Season the Boneless, Skinless Chicken Thigh (6) with Salt (1 pinch) and Crushed Red Pepper Flakes (1 pinch). Brown them in the pan for about 4 minutes on each side to develop some color. Transfer them to a plate.
Add Cremini Mushroom (10 ounce), Onion (1), and Garlic (4 clove) to the pan and let them cook for 3 minutes or so to soften and become fragrant.
Stir in the All-Purpose Flour (2 tablespoon) until the veggies become coasted and pasty. Then keep stirring while you pour in the Chicken Stock (2 cup) and Milk (1 cup).
Add the Dried Parsley (1 pinch), Salt (1 pinch), and Crushed Red Pepper Flakes (1 pinch) and let the sauce come to a low boil and gently bubble for a couple of minutes.
Stir in the Asiago Cheese (8 ounce) and Medium Pasta Shells (2 cup) and return the chicken to the pan. Let the mixture come back to a low boil, then cover the pan with its lid and transfer it to the oven.
Let it all bake together until the chicken is tender in the sauce and the pasta is perfectly cooked, about 25 minutes.
Take it out and sprinkle extra Asiago Cheese (to taste) on top. Serve immediately from the pan.