Cut chicken breast lengthwise to make 4 thin cutlets. Dredge each one in coconut flour on both sides.

In a large skillet or cast iron pan, heat the avocado oil. Once heated, place the chicken cutlets in and cook on medium heat for about 3 minutes per side. Be careful that the oil doesn't splatter, as it will be hot.

Place the cooked chicken on a plate lined with a paper towel to remove excess oil.

Add the tomato and mushrooms to the skillet and cook on medium heat for approximately 3 minutes, until they are both softened. Add in the spinach and cook for another 2-3 minutes, until wilted. Season with salt and red pepper flakes, and top directly on the chicken cutlets. Serve immediately.