Cook chicken first.
Cut chicken breast into cubed pieces.
Saute over medium heat with heated butter and oil for 10-15 minutes. Stirring occasionally.
Add onions and garlic with salt and peppers and saute for 3 minutes.
Add mushrooms and saute for another 2 minutes.
In a large cooking pot, bring 2 liters of water to boil. Add honey squash and cook for 10 minutes. Add tortellini to the same pot and cook for another 10 minutes (or as per package instructions). Drain.
Finely chop the cooked squash when cooled enough to handle. Keep some aside for slicing to add to top for color and decoration.
In a large mixing bowl combine all ingredients together and then transfer to a casserole dish.
Sprinkle shredded mozzarella.
Cover the casserole dish.
Bake at 370F for 10 minutes until the cheese is melted on top.