Cut each chicken breast in half horizontally to make 4 even-sized pieces. In a large shallow dish, mix flour, garlic powder, onion powder, salt and black pepper. Dredge each chicken piece in the flour mixture, shake off excess, and set aside.

In a large pan, heat 2 tablespoons of oil over medium-high heat. Cook the chicken for a few minutes on each side until they develop a golden crust and are nearly cooked through. Transfer them to a plate, lower the heat to medium.

In the same pan, toss in the spinach and cook for about 30 seconds until it starts to wilt, then take it out and set it aside.

Cook the onion for a couple of minutes until it's soft. If needed, add 1 tablespoon of oil to the pan.

Pour in the chicken stock and mix in the Boursin until it's well combined with the stock. Let it simmer for a few minutes until the sauce starts to thicken. Return the spinach and the chicken, simmer for about 30 seconds to thicken. If the sauce is too thick, add a bit of stock; if too thin, simmer more. 

Serve and enjoy!