Ranhofer's entry is a shape specification more than a method: the whole dish rests on cutting the potato square and frying it in two stages. The cross-reference to No. 2787 supplies the frying and dressing, so the practical work is knife work and oil temperature.
- The cut"Lardon shapes" means thick batons — 3/8 inch square by 2 inches long, roughly 1 cm by 5 cm. Square the potato into a block first and accept the trim as waste, or the pieces will not brown evenly.
- Frying in two stagesRanhofer gives no temperatures; the classical treatment of a baton this thick is a first, moderate bath until the potato is tender and pale but not coloured, a rest, then a hotter second bath to colour and crisp. Modern practice puts these at roughly 300-325F and 375-400F. A single fry risks colouring the outside before the centre is done.
- Dry the cut potatoesRinse off surface starch and dry them thoroughly on towels. Wet potato drops the oil temperature sharply and steams rather than fries.
- FatKitchens of this period generally fried in rendered beef fat or lard, which is worth trying for flavour; Ranhofer's own entries usually say no more than "hot fat". Any neutral oil with a high smoke point does the same job.
- "Dressed the same"The dressing is in No. 2787; Epicurean practice for fried potatoes is generally to drain, salt, and pile them on a folded napkin or paper. Salt as they leave the fat rather than before frying.
- Potato choiceUse a mealy, low-moisture potato — russet or a similar baking type. Waxy salad potatoes stay dense and will not go fluffy inside.
- YieldReckon one large potato per person as a garnish, two if the potatoes are the point of the plate. Fry in small batches so the oil holds its heat.
Pommes Pont-Neuf take their name from the oldest standing bridge in Paris, and the connection is traditionally traced to the fried-potato sellers who worked the bridge and the quays in the early nineteenth century, when the potato was still a fairly new item in Parisian street food. The cut is often described as the reference size against which the thinner allumette, paille and chip shapes were defined. Charles Ranhofer, chef at Delmonico's in New York, included it in The Epicurean (1894) as one entry in a long catalogue of potato garnishes, each distinguished chiefly by shape.