In a medium bowl, combine the flour, melted butter, water, eggs, sugar, cinnamon, and nutmeg until smooth.
Heat a cast iron skillet over medium-high heat. Add enough oil to cover the bottom of the skillet.
Using a spoon, drop spoonfuls of the churro dough into the hot oil. Fry the churros until golden and crispy, about 1-2 minutes per side.
Remove the churros from the skillet and place on a paper towel-lined plate. Sprinkle with the cinnamon-sugar mixture.
Melt the dark chocolate in the cast iron skillet. Dip the churros in the melted chocolate and serve warm.