1) Combine dry ingredients for batter in a bowl.
2) Combine room temperature milk and eggs in a bowl. Add wet to dry ingredients and combine well. Stir in melted butter.
3) Preheat oven to 425 degrees. Lightly butter a muffin or popover pan.
4) Pour a small dollop of batter into each popover tin. Then add a small pinch of ham and cheese to each tin. Pour batter over filling to cover. Fill each tin about 3/4 full.
5) Bake popovers for 15 minutes at 425, then reduce heat to 375 and bake for another 20-25 minutes.
6) Popovers are done when they are puffed and browned on top. Remove from oven and let cool briefly, then serve them up!