Step 1

Preheat the oven to 425°F and set an oven rack in the middle position.

Step 2

In a large bowl, whisk the eggs with the mustard, salt, and pepper. Whisk in the flour. Gradually add the milk, whisking until the batter is smooth. Stir in the cheese and chives.

Step 3

Melt the butter in a 10-inch cast iron or nonstick ovenproof pan over medium heat. Remove from the heat and swirl the butter around. Sprinkle the ham evenly around the pan. Pour the batter over the ham, then use a fork to be sure the ham is evenly distributed. Carefully transfer the pan to the preheated oven and bake for about 25 minutes. It will appear puffed straight out of the oven, but will quickly collapse. Cut the pancake into thin wedges and serve. (Remember that the pan is hot; I usually place a dishtowel or oven mitt over the handle as a reminder.)

Step 4

The pancake is best served fresh out of the oven. However, leftover slices can be reheated in the microwave.

Step 5

Note: Unlike a Dutch baby where the edges of the pancake will remain puffy after coming out of the oven, this pancake should puff up a bit in the oven to about 1½ inches high all over, then settle to about ½ inch high as it cools.