Special equipment: rimmed baking sheet, sieve
1. To make the dressing
: In a small bowl, mix together the buttermilk, sour cream
, mayonnaise, lemon juice, chives
, salt, and pepper until well blended. The dressing can be made up to 3 days in advance and stored in an airtight container in the fridge.
2. Place the eggs in a small saucepan, add cold water to cover, and bring to a boil over high heat. As soon as the water begins to boil, turn off the heat, cover the pan, and let the eggs sit for 15 minutes, or until cool enough to handle. Remove the eggs from the water. Working with one egg at a time, softly and gently crack each eggshell all around and carefully peel
it off while holding the egg under running cool water. Pat the eggs dry, halve lengthwise, and set aside.
3. In a large saucepan
, bring 3 quarts/2.8 L lightly salted water to a boil over high heat. While waiting for the water to boil, fill a large bowl about half full with ice and then add cold water just to cover the ice. Line the baking sheet with paper towels.
4. Drop the carrots into the boiling water and boil for 3 to 4 minutes. Using the sieve, remove the carrots
from the water and plunge them, sieve and all, into the ice bath. Remove the carrots from the ice water, drain
, and dump them out onto the prepared baking sheet. This process, called "shocking," will halt the cooking so the vegetables retain their bright color and fresh crunch.
5. Bring the water back to a boil and repeat with the peas, leaving them in the boiling water for about 30 seconds, and then with the green beans, leaving them in the boiling water for 2 to 3 minutes, before shocking each of them, in turn, in the ice water and transferring them to the baking sheet. Replenish the ice bath as needed with more ice to keep it ice-cold.
6. Bring the water back to a boil and add the potatoes
. Reduce the heat to medium and simmer
for 10 to 12 minutes, or until you can pierce them easily with a fork. Shock the potatoes in the ice water, scoop them out, and then dump them onto the baking sheet with the other vegetables.
7. Decoratively arrange the lettuce
, tomatoes, eggs, potatoes, carrots, peas, and green beans in four shallow salad bowls. Serve the dressing on the side.