Place a cast-iron skillet on the warm griddle. Add butter, brown sugar, cinnamon, and nutmeg to the skillet, stirring as it melts. Mix in the apple slices.
In a bowl, whisk together apple cider and cornstarch. Add some to the apple mixture and continue stirring while heating to a simmer.
Add pecan pieces and mix them in. Let simmer until apples are cooked through.
