Recipe

Make Filling

1. Line baking pan with plastic wrap, or lightly oil. In small pot on medium heat, warm up milk until almost simmering. In medium saucepan on medium heat, melt butter. Stir in flour and cook, stirring, for 5 minutes to make roux, ensuring it doesn’t take on any coloration. Slowly pour in hot milk while whisking constantly, until mixture becomes smooth and thick. Season with salt, pepper, cayenne and nutmeg.
2. Lower heat to the minimum and add egg yolks, whisking constantly. Cook for 1 minute, without simmering or boiling. Turn off heat and gradually whisk in Parmesan and Gruyère.
3. Pour mixture into prepared pan to depth of 3⁄4″. Place layer of plastic wrap directly on surface of béchamel to prevent forming skin. Refrigerate for several hours, until fully set — or, better yet, a full day.

Assemble And Fry Croquettes

1. Unmold béchamel and, using hot knife, slice into 1″ squares.
2. To bread squares, set up station for yourself with 3 bowls: first with flour, second with beaten eggs and third with breadcrumbs. Coat square with flour, then dip in egg mixture, and finally coat in breadcrumbs. Make sure each square is coated evenly.
3. Preheat oven to 350°F with rack in center position. Line baking sheet with parchment paper. In deep fryer or large pot, heat oil to 375°F. Working in batches of 6 to 8 squares at a time to avoid crowding and cooling oil too quickly, use slotted spoon to slowly lower breaded squares into oil. Cook until golden brown, 2 to 3 minutes. Insert tip of paring knife into centre of square and make sure it’s hot by testing temperature of tip of knife against your lower lip. If not hot enough, transfer squares to prepared baking sheet and finish in oven for 4 to 5 minutes.