Moules-frites

Method

1. Put the mussels in a colander under cold running water. Pull off the hairy beard by tugging it towards the hinge, and scrape off any barnacles with the back of a knife. Throw away mussels with cracked shells. If one is open, tap it on the counter: if it does not close within a minute, it is dead and must go. Keep the cleaned mussels in a bowl in the fridge under a damp cloth (never submerged in water).

2. Peel the potatoes and cut them into sticks 1 cm thick. Rinse them, then leave them in a bowl of fresh cold water for 15 min to wash off surface starch. Drain and dry them very thoroughly with a clean towel: wet potatoes make hot oil spit.

   Add in this stepFloury potatoes 600 g

3. Pour the oil into a deep, heavy pot (22 cm, 2×: pot size, number of batches); it must be no more than half full. Heat over medium-high heat to 160 °C: use a thermometer, or check that a wooden chopstick is surrounded by steady small bubbles. Fry the potatoes for 5 min per batch, until soft and limp but still pale. Lift out with a slotted spoon, drain on a rack or kitchen paper and rest for at least 10 minutes. Never leave hot oil unattended; if it smokes, turn off the heat. Smother any flames with a lid, never with water.

   Add in this stepSunflower oil (or beef dripping) for frying 1½ L

   medium-high heat

4. Meanwhile, finely chop the onion, thinly slice the celery and chop the garlic and parsley.

5. Reheat the oil over medium-high heat to 180 °C. Fry the potatoes a second time for 2 min per batch (×2) until deep golden and crisp, then drain and salt them at once. Keep them warm on a rack in a 100 °C oven and turn off the oil.

   Add in this stepSalt ½ tsp

   medium-high heat

6. Melt the butter in a large lidded pot (24 cm) over medium heat. Add the onion, celery and garlic and cook for 4 min, stirring, until soft and translucent but not browned.

   Add in this stepButter 25 gOnion 1Celery stalks 1Garlic cloves 2

   medium heat

7. Turn the heat up to high heat, pour in the wine and bring it to a boil. Add the mussels and a few grinds of pepper, cover tightly and cook for 5 min, shaking the pot firmly once or twice with the lid held down, until all the shells have opened wide. Scatter over the parsley and toss. Discard any mussels that stay closed.

   Add in this stepDry white wine 150 mlLive mussels in their shells 1,000 gBlack pepper to tasteFlat-leaf parsley, chopped 2 tbsp

   high heat

8. Ladle the mussels and their broth into deep bowls, with an empty bowl for the shells. Serve the fries on the side with mayonnaise for dipping. Use an empty shell as tongs to pick out the mussels, and dip fries or bread into the broth.

   Add in this stepMayonnaise 4 tbsp