Preheat the oven to 220C/200C Fan/Gas 7.
Mix the duck fat, potatoes and garlic together in a bowl. Season with salt and pepper.
Place a circle of greaseproof paper in a medium frying pan and then add the potato mix in a flat layer. Cook for 5 minutes, then place in the oven for 5–10 minutes, until the potatoes are golden.
Remove from the oven and top with the cheese then return to the oven for 5 minutes.
Serve whole with a green salad, some charcuterie and cornichons on the side.
