1. Prepare the Béchamel sauce: Melt the butter in the saucepan. Whisk in the plain flour and cook for a few seconds to create a roux. Gradually whisk in the hot full-fat milk, stirring constantly until the sauce thickens into a smooth, velvety consistency. Remove from the heat and stir in the ground nutmeg and add the grated Comté cheese. Season to taste with salt and black pepper.
2. Pre-heat the oven to 200C/400F/Gas mark 6
3. Spoon some of the sauce over the base of an oven proof gratin/baking dish. 
4. Spread some Dijon mustard over each pancake, then place a slice of ham and cheese on the top. Roll the pancakes up and place them in the gratin/baking dish. 
5. Spoon the remaining béchamel sauce over the stuffed pancakes, and sprinkle the grated Comté cheese over the top. 
6. Bake for 20 to 25 minutes until golden brown and bubbling. 

Pancakes: 

125g plain flour
Pinch of salt
1 medium egg
300ml milk
25g melted butter

1. Mix flour and salt in a basin, make a hollow in the centre and drop in the egg. Stir with a wooden spoon and add the milk gradually, until all the flour is worked in.
2. Beat well and add remaining milk and the melted butter.
3. Cooking: heat a small amount of butter in a frying pan. When it begins to smoke, pour approximately 3 tablespoons into the frying pan. When golden brown underneath, turn and cook other side.