Moules-Frites

Instructions

1. 1 Start the frites first. Cut the peeled potatoes into batons about one centimetre thick and eight centimetres long. Rinse them thoroughly in cold water to remove surface starch, then pat completely dry with clean tea towels.
2. 2 Heat the frying oil to 150C (300F) in a deep heavy pot or fryer. Blanch the potato batons in small batches for six to eight minutes until they are cooked through and pale without any colour. Remove and drain on a wire rack. This first fry can be done hours ahead.
3. 3 Sort through the mussels, discarding any that are cracked, broken, or that remain open when tapped sharply on the counter. Pull off any remaining beards. Rinse the mussels in several changes of cold water to remove grit and sand.
4. 4 Melt the butter in a very large lidded pot over medium heat. Add the diced shallots, celery, and garlic, cooking gently for three to four minutes until softened and fragrant but not browned.
5. 5 Turn the heat to high, pour in the white wine, and let it bubble for thirty seconds. Tip in all the mussels at once, cover tightly with the lid, and cook for five to seven minutes, shaking the pot vigorously two or three times during cooking.
6. 6 The mussels are done when they have all opened. Discard any that remain stubbornly closed after cooking. Stir the chopped parsley through the mussel cooking broth, which will have become a wonderfully flavourful liquor.
7. 7 While the mussels cook, reheat the frying oil to 190C (375F) for the second fry. Fry the blanched potato batons again in batches for two to three minutes until they are deeply golden, crispy on the outside, and fluffy within.
8. 8 Serve the mussels immediately in their pot or in deep warmed bowls, with the aromatic broth poured over. Place the frites in a separate cone or bowl alongside, with a ramekin of homemade mayonnaise for dipping the frites.