Instructions

1. Prepare the leeks: Place the sliced leeks into a colander and rinse them well, rubbing to loosen any dirt. Rinse them again and drain well. (There is no need to dry them, as the residual water is useful in cooking the leeks.)
2. Heat a large Dutch oven or skillet on medium-high for 1 to 2 minutes. Add 2 tablespoons of olive oil, along with the leeks. Season generously with salt and black pepper and cook, stirring occasionally, until the liquid cooks off and leeks start to stick to the pan, 5 to 6 minutes. Stir in the garlic and thyme. Reduce heat to low, cover, and cook for 20 minutes, stirring occasionally.
3. Meanwhile, bring a medium pot of water to a boil over high. Add the eggs and continue to cook over medium-high for 7 minutes. (Make sure you set a timer.) Set up an ice bath. Using a spider ladle or slotted spoon, remove the eggs from the water and immediately add them to the ice bath. Cool for 3 to 4 minutes, then peel and set aside.
4. Make the vinaigrette: In a large bowl, whisk together the miso paste, Dijon mustard, garlic, vinegar and olive oil.
5. Uncover the leeks — they will have reduced into a silky, jammy consistency. Discard the thyme, transfer the leeks to the bowl and stir to coat in the miso vinaigrette.
6. Stir in the white beans and leave to cool for a few minutes. Add about ¾ of the tarragon or parsley leaves and toss gently to combine.
7. Divide the leeks and beans among bowls and drizzle each with olive oil. Top with a halved jammy egg and finish with the remaining herbs. Serve with toast, if desired.