Leeks Vinaigrette (Poireaux Vinaigrette)
Poireaux vinaigrette is one of those cold French first courses that looks like restraint and tastes like generosity: whole leeks, braised until they surrender, then left to soak in a bracing mustard vinaigrette. It belongs to the wider European table as much as the French one, the kind of make-ahead vegetable dish that improves for sitting. The two things that matter are washing the grit out of the layers before cooking and cooking the leeks all the way to silky, since a leek pulled early stays stringy. The dressing needs no oil because mustard does the emulsifying, thickening vinegar and shallot into something that clings and seeps into every layer. Serve it cold, alone or beside a grain, and make it hours ahead.
Ingredients
- 6 wholes Leeks, trimmed to white and pale green
- 1 tbsp Dijon mustard
- 3 tbsp White wine vinegar
- 1 whole Shallots, finely minced
- 1 tbsp Lemon juice
- 1 tbsp Capers, rinsed, chopped
- 3 tbsp Flat-leaf parsley, chopped
- 1/2 tsp Black peppercorns, freshly ground
Method
- Halve each leek lengthwise almost to the root, keeping the layers attached, and rinse hard under running water to flush the grit from between them. Leeks trap soil deep in their layers, and a cold cross-section that grinds in your teeth is what ruins this dish; splitting and rinsing before cooking is the only reliable fix.
- Lay the leeks in a wide pan, add water to just cover, and simmer until a knife slides through the thickest part with no resistance, 12 to 15 minutes. They must be fully, almost collapsingly tender: undercooked leeks are stringy and squeak, while properly braised ones turn silky and sweet.
- Lift the leeks out and lay them on a clean towel, then press gently to squeeze out the water they hold. Draining and pressing keeps the vinaigrette from being diluted into a puddle by the water trapped in the layers.
- Whisk the mustard, vinegar, lemon juice, and minced shallot into a thick dressing. Mustard is the emulsifier that lets this be a real vinaigrette with no oil: it binds the acid into a clingy, opaque dressing, while the raw shallot softens in the vinegar as it sits.
- Arrange the leeks on a platter, spoon the vinaigrette over so it settles into the layers, and scatter the capers, parsley, and black pepper. Let them marinate at least 20 minutes, or up to a day cold. Time is an ingredient here: the leeks drink in the dressing as they sit, which is why it is best made ahead.
Nutrition
Estimated per serving: 90 calories, 3 g protein, 3 g fiber, 150 mg sodium. Computed from USDA FoodData Central reference values for the main ingredients. This is an approximation, not a laboratory measurement. How these are computed.
Cost per serving is estimated from US national-average retail prices for cheap staple forms, using BLS dried-bean prices and USDA produce prices. Prices vary by store and season, so treat it as a guide, not a receipt. How this is computed.
