Cut the chicken breast into 1" pieces. If you are using an onion, slice it very thin
Add 2 tablespoons of cooking oil to a large skillet on medium heat.
Season the chicken with the black pepper, seasoning salt, 1/2 tsp garlic powder, and 1/2 tsp of sea salt. Add the onions and the chicken to the pan and turn the chicken once the first side is golden brown.
Boil your pasta. remember that you will be reserving some pasta water to add to your sauce.
Once the chicken is browned on both sides and cooked through, remove the chicken and onions from the pan. Set aside.
Add your boursin and broth to a pan on low heat. Let the cheese melt and create a creamy sauce. Once your pasta is done boiling, add 1/4 cup of pasta water to your sauce and bring the sauce up to a boil.
Once the sauce boils, turn the heat down to medium low and add in your spinach with remaining salt and garlic powder. Mix well. Once it starts to wilt, add in your chicken and onions. Remove from heat once the spinach is completely wilted.