Add the chicken, cauliflower, bell pepper, garlic and spinach to a large resealable freezer bag.
Squeeze out as much of the air as you can, and seal the bag.
Refrigerate until ready to use.
To make the sauce, in a large measuring cup combine all the ingredients.
Cover with plastic wrap and refrigerate until ready to use.
Add the pre-cut ingredients to a large skillet.
Add the sauce and toss to combine.
Cover with a lid and cook over medium heat for 25-30 minutes, stirring frequently until the chicken is cooked through and the sauce is just thickened.
If necessary, add a little water or chicken stock during cooking.
Taste and add more salt or black pepper if necessary.