Combine the chicken tenderloins, salt and olive oil in a bowl. Place a large saucepan or casserole dish over medium heat. Pan fry the chicken tenderloins each side for about 4 minutes. Remove and set aside.
To the same pan over medium–high heat, add the butter and some more olive oil if needed. Add the onion and cook, stirring, for 2–3 minutes. Add the garlic, bacon and mushrooms and cook, stirring, for 3–4 minutes. Add the stock and cream and whisk well. Then add the tortellini. Place the lid on, turn the heat down to medium–low and cook for 3–4 minutes.
Remove the lid and give the tortellini a gentle stir. Add the spinach and parmesan and mix through gently. Return the chicken to the pan. Turn off the heat and add some pepper and parsley (if using).