I find chicken breast to be dry and unintersting so when there are leftovers to be microwaved, I usually put a huge dollop of bacon grease or coconut oil on top along with some spices like mole powder, curry, or taco seasoning. Mixed with the melted fat it makes a nice low carb “sauce”. Another technique is olive oil, lemon juice and powdered parmesan cheese for a more Italian flavour.

You could also just microwave the fat and spices in a small bowl for dipping the chicken.