Preheat oven to 375° F. Grease muffin tin with cooking spray. You could also use a square pan.
Combine wet ingredients in one bowl - milk, melted butter, oil, and egg. In a separate bowl, combine dry ingredients - flour, cornmeal, sugar, cream of tartar, and baking soda.
Pour wet ingredients into dry ingredients and mix until just incorporated. Gently fold in corn, chiles, and cheese.
Pour batter into prepared pan and bake for 23-25 minutes if using muffin tin, or 25-28 minutes if using square pan.
