In a mixing bowl, whisk together the flour and the eggs. Gradually add in the milk and water, stirring to combine. Add the salt and butter; beat until smooth.
Heat a lightly oiled griddle or frying pan over medium high heat. Pour or scoop the batter onto the griddle, using approximately 1/4 cup for each crepe. Tilt the pan with a circular motion so that the batter coats the surface evenly. Try not to make them too thick or too thin.
Cook the crepe for about 2 minutes, until the bottom is light brown. Loosen with a spatula, turn and cook the other side. Immediately sprinkle on top with some cheese, ham, mushrooms, and corn.
Let it cook, until bottom is golden brown and fold it in an envelope shape.
Remove and serve immediately. Repeat the same process for the rest of the ingredients. Enjoy!