Preheat oven to 350 degrees F.
In a bowl, beat the egg with 1 tablespoon of the milk. Add the flour and mix until smooth. Incorporate the rest of the milk little by little. Strain the mixture through a fine mesh sieve to remove lumps. Melt 1 tablespoon of the butter in an 8-inch nonstick skillet over medium-low heat. Let the butter cool and add to the batter. Heat the same pan again and ladle enough batter in pan to coat the bottom. When the edge of the crepe begins to color, turn it over and cook the other side for a few seconds. Repeat process until all of the batter is gone.
Lay out crepes on a countertop, place 1 slice of ham and fontina on top and fold in half to form a half-moon and again to form a triangle. Repeat with remaining crepes, ham, and fontina.
In a small saute pan, brown remaining 1 tablespoon butter with the sage. Pour into a baking dish. Arrange crepes around dish so they don't overlap. Pour the cream over the crepes, sprinkle the finely grated Parmesan cheese and bake in oven until the top is golden brown.
Serve while hot.
This recipe was provided by professional chefs and has been scaled down from a bulk recipe provided by a restaurant. The FN chefs have not tested this recipe, in the proportions indicated, and therefore, we cannot make any representation as to the results.