Instructions

1. Trim the dark green parts from 1 large or 2 small leeks. Thinly slice the white and light green parts crosswise. Place in a bowl of cold water and agitate slightly to separate the rings and release any sediment. Let sit for 2 minutes. Lift the leeks from water and transfer to a heatproof bowl, leaving any sediment at the bottom of the bowl.
2. Place 3/4 cup red wine vinegar, 2 teaspoons of the granulated sugar, and a pinch of kosher salt in a large saucepan and bring to a simmer over high heat. Pour the mixture over the leeks and push the leeks down with a spoon to submerge as much as possible (it’s okay if they are not totally submerged). Set aside to pickle while you prepare the rest of the salad, stirring every 5 minutes or so.
3. Fill the same large saucepan with water, add a few large pinches of kosher salt, and bring to a boil over high heat. Prepare an ice bath by filling a large bowl halfway with water and ice. Add 10 ounces frozen peas to the ice bath; the peas might stick to the ice cubes in the bowl but will separate once you add the hot asparagus.
4. Trim and discard the ends from 2 bunches asparagus and cut the asparagus crosswise into thirds. Trim the ends from 2 small Belgian endives and cut lengthwise into quarters. Separate the leaves into a large bowl. Cut 1 small head radicchio in half lengthwise; remove the core and cut each half into 4 to 5 wedges. Separate the wedges into the same bowl. Coarsely chop 1 bunch fresh dill and the leaves from 1 bunch fresh mint until you get 1/2 cup each. Add the herbs to the bowl.
5. Working in batches if needed, add the asparagus to the boiling water and cook just until bright green and crisp tender, 2 to 3 minutes. Transfer with a wire spider or a slotted spoon to the ice bath.
6. Coarsely chop 1 cup walnuts and/or pecans. Place the nuts and 1/2 cup olive oil in a medium skillet. Cook over medium heat, stirring frequently, until the nuts are deeply toasted and fragrant, 4 to 6 minutes. Transfer the nuts with a slotted spoon to a paper towel-lined plate. Sprinkle with kosher salt. Reserve the oil to use in the dressing.
7. Place 1/3 cup of the leek vinegar, 2 tablespoons Dijon mustard, 2 teaspoons kosher salt, and remaining 1 teaspoon granulated sugar in a small bowl and whisk to combine. While whisking continuously, slowly drizzle in the nut oil and whisk until combined. Taste and season with kosher salt as needed.
8. Drain the asparagus and peas; shake well to remove as much water as possible. Add to the bowl of greens and herbs. Drizzle with as much dressing as desired and toss to combine. Top with the pickled leeks and toasted nuts.