Heat some of the olive oil in a cast iron skillet over medium high heat. Season your thin sliced breasts with salt and pepper. Add your chicken breasts to the hot skillet in a single layer.

Cook chicken for 2-3 minutes or until starting to brown. Then flip your chicken to brown the other side for another 2-3 minutes. Remove chicken from skillet and set aside.

With the skillet still over medium add the rest of the olive oil to the pan. Add in the onions and sir to soften for 1-3 minutes. As the onions begin to soften add in the garlic and stir for about 1 minute.

Fold in the spinach with the garlic and onions until the spinach starts to wilt. Once the spinach has wilted after about 1-3 minutes add in the chicken stock and sun dried tomatoes to a high simmer.

Add in the cream cheese and mix in until the cream cheese is fully melted into the spinach mixture. SPrinkle in the xanthan gum and stir in to thicken the sauce. Do NOT overuse the xanthan gum. Taste for seasoning and possibly add salt and pepper at this point.

Place the chicken (and the juices from the plate of the chicken) back into the creamy spinach and sun dried tomato mixture. Spoon the sauce over the chicken and let simmer for 7-10 minutes.