Preheat the oven to 375 degrees F (190 degrees C) and get out a large, oven-safe skillet with deep sides.
Heat the Olive Oil (1 dash) in the skillet over medium high heat. While it heats up, generously season the Boneless, Skinless Chicken Thigh (5) on both sides with the Salt (2 pinch), Ground Black Pepper (2 pinch) and Garlic Powder (2 pinch). Then brown the chicken for 4 minutes on each side in the skillet and transfer to a plate.
Add the Onion (1), Garlic (3 clove), and Artichoke Hearts (1 can) to the pan. Let them get soft for a minute, then add in Fresh Baby Spinach (3 cup) and stir it in to wilt for another minute.
Stir in the Dijon Mustard (1 tablespoon) and White Wine (1/4 cup) and let them cook for another minute with everything. Finally, pour in the Milk (1/2 cup), Chicken Stock (1/4 cup) and Corn Starch (1 teaspoon).
Give the sauce and stir, letting it bubble for a minute. Then return the chicken to the pan and let it sit in the sauce for another couple of minutes while you sprinkle the Grated Parmesan Cheese (1/4 cup) on top.
Transfer the skillet to the oven and bake for about 25 minutes. When it's done, plate it directly from the skillet and serve with your favorite sides!