Put a chicken breast onto a chopping board and, with your hand flat on top of it, use a sharp knife to slice into one side of the breast, starting at the thicker end and ending at the thin point, being careful not to cut all the way through to the other side. Open out the breast like a book. Repeat with the remaining chicken.

Lay one butterflied chicken breast between two sheets of baking parchment, and bash using a rolling pin until it’s about 3-4mm thick. Repeat with the remaining chicken breasts.

Lay a slice of ham over each chicken breast, then sprinkle over the cheese. Roll up each chicken breast from a short end into a chunky cylinder (use a cocktail stick to secure it in place, if needed). Chill for 30 mins to firm up.

Heat the oven to 220C/200C fan/gas 7 with two baking trays inside to heat up for at least 10 mins. In a shallow bowl, combine the breadcrumbs, melted butter and a little seasoning. Tip the flour into another shallow bowl and season lightly. Tip the egg into a third.

Remove the cocktail sticks from the chilled chicken, if needed. Working with one chicken breast at a time, dip it into the flour to coat, followed by the egg mixture, shaking off any excess. Coat in the breadcrumb mixture. Repeat with the remaining chicken breasts.

Carefully remove the heated trays from the oven and line with baking parchment. Arrange the chicken on the trays and return to the oven for 25 mins, or until golden and cooked through.

Meanwhile, make the sauce. Melt the butter in a pan over a low heat. Stir in the flour and cook for a couple of minutes. Gradually pour in the milk, stirring continuously to prevent lumps. Turn the heat up to medium and cook, stirring occasionally until thickened. Remove from the heat and stir through the mustard, cheese and some seasoning. Serve the chicken with the sauce spooned over and a salad on the side, if you like.