Pommes Anna with rosemary-garlic butter

Infuse the butter in a small saucepan over low heat with a big sprig of rosemary and deeply smashed garlic, just to a gentle simmer; do not brown or season it.

Rinse and peel the potatoes.

Work one potato at a time so the slices need no soaking: slice thin on a mandolin, flexible but not paper thin, gripping with the palm.

Brush a thin layer of infused butter on the skillet; arrange the first layer as a tight, overlapping rosette from the centre out.

Drizzle butter, season with salt and pepper; repeat layers, butter and seasoning to about two thirds up the skillet, five layers, filling gaps with small pieces.

Finish with the last butter, salt and a couple of rosemary sprigs.

Cook on the burner over medium, then high, until the bottom layer is golden brown, not too dark.

Cover with foil, weight with a Dutch oven and bake at 375 for 20 to 30 minutes, until a cake tester shows the potatoes tender; set a sheet tray or foil underneath for dripping butter.

Cool about 10 minutes so the starches set; loosen with a spatula if needed.

Invert onto a platter and cut with a serrated knife.