Prepare chicken (if using chicken breasts). Slice chicken breasts in half lengthwise to create evenly sized cutlets. Season chicken with salt and pepper on both sides.
Cook chicken. Add 1 tablespoon of butter to a large skillet over medium heat and let it get hot. Add chicken and cook for 3-5 minutes until golden brown on one side. Flip and cook another 3-4 minutes until golden brown and cooked through. Remove from the pan and set aside. You may need to cook the chicken in batches, depending on how big your pan is.
Make the slurry. In a small bowl, make a slurry by adding 2 tablespoons of broth (from the 1 1/2 total cups) along with the tapioca flour and whisk to combine. Set aside.
Make sauce. Add the remaining 1 tablespoon of butter to the pan and let it melt. Add the onion, salt, and pepper, and saute for 3-4 minutes until softened. Then add the garlic, and saute for another 30-60 seconds. Next, add cream cheese, bone broth, red pepper flakes, salt, and pepper, and whisk to combine until the cream cheese is melted. Give the slurry another good stir to make sure it is combined, and add it to the pan. Let thicken for 2-3 minutes, whisking constantly.
Assemble. Add spinach and artichokes, mixing to combine and allowing the spinach to wilt. Finally, add cooked chicken back into the pan, along with its juices, nestling it into the sauce, and let it warm through.
Enjoy! Serve over rice or pasta.