Place chicken breasts on a plate or cutting board. Using a jacquard tool or fork, poke several holes in the meat. If using a fork, I like to stab it 10 to 15 times on each side of the chicken breast. Place chicken in a dish or a gallon sized ziploc bag.

Wash hands thoroughly. Pour italian dressing over top, coating chicken. Place in the fridge.

Let chicken sit in the marinade for 2 to 24 hours, depending on your schedule. The longer it sits, the more flavorful your dish will be.

Once chicken is done marinating, it's time to cook!

Preheat oven to 400 degrees F.

Heat cast iron skillet over medium high heat. Add oil to pan and then place chicken breasts carefully in. Cook for approximately 5 minutes to thoroughly brown, not moving so that a deep brown color forms. Flip and repeat on the over side. Remove to a clean plate to the side.

Reduce heat to medium and add butter. Add sliced mushrooms and onions, sauteeing until both are softened and fragrant, around 5-7 minutes. Add water and scrap up all of the extras bits on the bottom of the pan, as there is a lot of flavor there.

Add spices and stir. Move mushrooms and onions to the side of the skillet and place chicken breasts back into the skillet. Carefully scoop mushroom-onion mixture over top, splitting between the two pieces of chicken.

Top with cheese slices and place in preheated oven.

Cook for 10 minutes, until chicken is cooked through and cheese is melted and starting to brown.