Pommes de Terre à la Duchesse

Ingredients

Equipment Needed

• •Light-coloured heavy baking sheet
• •Large piping bag
• •½-inch (12 to 15 mm) open-star piping tip
• •Digital scale
• •Soft pastry brush
• •Thin offset spatula

Instructions

1. 1

   Heat the oven

   Set a rack in the upper third of the oven and heat it to 475°F (245°C), or 450°F (230°C) with convection, for a full thirty minutes. Spread the softened butter in a thin, complete film over a light-coloured metal baking sheet. Use the bare buttered tray called for in the preparation, not parchment; the direct contact helps the bases colour and release cleanly.

   A dark tray can scorch the butter and potato bases before the ridges colour. Light aluminium gives you a calmer eight minutes.
2. 2

   Portion the paste

   Bring the prepared potato paste from Croquettes de Pommes de Terre (No. 2210) to cool room temperature. Divide it into twelve equal two-ounce portions, about 57 g each, preserving the book's portion exactly while reducing only the total quantity. Keep the portions covered as you work so the surface doesn't form a skin. Don't loosen the paste with milk or cream; a softer table purée cannot hold the shape this dish requires.

3. 3

   Shape the duchesse

   Fit a large piping bag with a ½-inch (12 to 15 mm) open-star tip and fill it no more than two-thirds full. Pipe each portion into a broad fluted mound about 2 inches (5 cm) across, finishing with a smaller crown to suggest a cottage brioche. Leave 1½ inches (4 cm) between pieces. You may instead mould equal galettes, flat rounds about ¾ inch (2 cm) thick, or small loaves, but keep one shape and one height across the tray so everything colours together. If the ridges slump, the paste is too warm. Scrape it back into the bag, chill it for ten minutes, and pipe again. If it tears and refuses to flow, leave the filled bag at room temperature for five minutes and massage it gently with your hands. Don't add liquid. Ça se rattrape.

   Press with steady pressure and stop squeezing before lifting the bag. A hesitant squeeze leaves broken ridges; one confident motion gives the fierce oven a clean surface to gild.
4. 4

   Gild with egg

   Beat the egg only until the white and yolk lose their separate identities, keeping it fluid rather than frothy. Gild each shape with the thinnest possible coat, brushing upward along the ridges so you don't flatten them. The egg should shine, not collect in the hollows. If it pools around a base, lift the excess at once with a clean, nearly dry brush; pooled egg cooks into a rubbery yellow skirt.

5. 5

   Colour them fiercely

   Bake immediately in the upper third of the fierce oven for seven to eight minutes. Keep the door closed for the first six. The duchesse are ready when the raised ridges are deep butter-gold, the hollows remain a shade paler, and the bases have taken a fine bronze edge. If the colour is uneven at seven minutes, turn the tray and move it one rack higher for the final minute. Don't lengthen the bake simply to chase a darker crust; the tender centre is part of the dish.

6. 6

   Serve at once

   Let the duchesse stand on the tray for one minute, just long enough for the gilded surface to settle, then lift them with a thin offset spatula onto a warm serving platter. Don't cover them, since trapped moisture softens the ridges. Serve beside a roast or sauced main course, placing any jus around the potatoes rather than over their bronzed tops. À table!

Chef Tips

• •The first piped shape is your test. If its ridges hold sharply for a full minute, pipe the tray; if they relax, chill the paste briefly. Moisture control decides the dish before the oven ever sees it.
• •Use a sturdy reusable piping bag and a large open-star tip. A tiny tip forces you to overwork the paste, while a thin disposable bag may split under the pressure.
• •Choose one form per tray. Brioche shapes, galettes, and small loaves all belong to the source, but mixed heights colour at different speeds in an eight-minute bake.
• •Serve pommes duchesse with roast poultry, beef, or veal and a proper jus. Spoon the sauce around them at the table so the piped ridges remain crisp-edged. We don't apologize for butter, but we don't drown good work either.

Advance Preparation

• •The prepared potato paste from Croquettes de Pommes de Terre (No. 2210) may be refrigerated for up to one day with covering pressed directly against its surface. Let it stand at room temperature for about twenty minutes before testing its piping consistency.
• •The duchesse may be piped onto the buttered tray up to four hours ahead. Chill them uncovered for fifteen minutes, then cover loosely. Bring them out while the oven preheats, and gild only immediately before baking so the egg coat stays even and glossy.
• •For the source's seven-to-eight-minute finish, the shaped potatoes must not enter the oven refrigerator-cold. Let them lose their deep chill for fifteen to twenty minutes without allowing the ridges to soften.

Frequently Asked Questions

Nutrition Information

1 serving (3 pieces, about 170g)