Butterfly the 210 g chicken supreme horizontally, leaving one edge attached.

Lightly flatten the chicken and season the inside with salt and black pepper.

Place the ham slice and 38 g cheese over one side of the chicken.

Fold the chicken tightly over the filling and wrap it in plastic wrap.

Chill the wrapped cordon bleu in the freezer for 30 minutes.

Season the flour with salt and black pepper in a shallow plate.

Beat the egg in a mixing bowl and place breadcrumbs in a second bowl.

Coat the chilled cordon bleu in seasoned flour, then dip it in egg.

Press the cordon bleu firmly into breadcrumbs until fully coated.

Slice the potatoes into very thin matchsticks and rinse them in cold water.

Dry the potato matchsticks thoroughly with a kitchen towel.

Heat frying oil to 160–170 °C in a deep pot.

Fry the potatoes in one batch, stirring regularly until pale golden and crisp.

Drain the shoestring potatoes and season them immediately with salt.

Heat neutral oil and butter together over low heat in a frying pan.

Cook the breaded cordon bleu gently, turning with tongs until golden and cooked through.

Rest the cordon bleu for 3 minutes and serve with the shoestring potatoes.