Preheat the oven to 400 degrees F.

In a saute pan over medium heat, melt the butter, then add the flour and cook together, stirring vigorously to make a paste. Using a whisk, stir in the chicken stock and milk. Let it thicken for about 1-2 minutes. Make sure it doesn’t get too thick like a porridge. If it does, thin it out with more milk. Turn off the heat and add in your Gruyere cheese. Taste and season with salt if needed.

To assemble the crepes, place them on lightly greased baking sheets. Lightly spread with mustard on the bottom left quarter of each crepe, add two or three slices of deli ham, then top with a tablespoon of cheese sauce. Fold the crepes in half, over the filling, then fold again into quarters, to make a triangular shape.

Spoon another tablespoon of sauce on the tops of each of the folded crepes and spread it around a bit. Bake for 5 minutes. Turn on the broiler and broil for 2-3 minutes, or until the topping is bubbly and lightly browned. Serve hot. Garnish with sliced scallions or any fresh herbs of your choice.