Preheat oven to 400F
Cut potatoes in bite size pieces
Spray/spread cooking oil on sheet pan (or lay down a layer or foil/parchment paper so nothing sticks) and spread potatoes out evenly and cook for 10 minutes or until soft
While the potatoes are cooking, place butter into a medium size microwave safe bowl and microwave about 1 minute or until melted.
Mix water, salt, pepper, garlic and onion with the butter and put it to the side until ready to use
Cut the chicken in to cubes
Take potatoes out of the oven and place the diced chicken, broccoli and carrots on to the sheet pan.
Pour butter mixture evenly throughout the sheet pan. Grab tongs or use your hands to make sure everything is coated.
Place the sheet pan into the oven at 400F for about 20 minutes until the chicken is fully cooked on the inside
Once out of the oven sprinkle parmesan cheese on top and serve.