Peas embody spring to me, and there are so many shapes and sizes to choose from. Sugar snaps have a sweet and grassy flavor; snow peas have a wonderful crunch. I also love frozen peas. Defrosted and used as is, they add a starchy comfort that takes me to childhood. Small, simple touches make this salad come out better: adding a pinch of sugar to the peas enhances their sweetness, blanching and cooling them in an ice bath assures they are crisp and cold, and thoroughly drying them off before coating them in the vinaigrette prevents the flavors from diluting. When the peas are coated with the "bite" from the mustard and the saltiness of the capers, they come to life.
Make the vinaigrette: In a medium bowl, whisk together the Dijon mustard, red wine vinegar, lemon zest and juice. Add the capers, caper brine and a pinch of salt and pepper, to taste. Slowly whisk in the olive oil. Taste and reseason, only if needed. Set aside.
Prepare an ice bath. Fill a large bowl halfway with ice cubes and add some cold water. Put a colander squarely inside the ice bath. The colander will keep you from having to pick the peas out from amongst the ice cubes in the ice bath.
Blanch the peas: Bring a medium pot of water to a boil over medium heat. Add salt until the water tastes like seawater. Add the snow peas and cook until crisp-tender, about 1 minute. Remove the peas from the water with a strainer and transfer them to the colander inside the ice bath. Bring the water back up to a boil. Add the sugar snap peas and cook until crisp-tender, about 1 minute. Use the strainer to remove the peas and plunge them into the colander inside the ice bath. Allow them to sit in the ice water to assure they have cooled thoroughly. Discard the blanching water.
Finish: Remove the peas from the ice bath and spread them out onto the kitchen towel over flat surface. Use another kitchen towel to gently pat them dry. Transfer the towel to a plate and put the peas into the refrigerator to chill until you are ready to serve.
Assemble: Toss the sugar snap peas, snow peas and defrosted peas with a sprinkle of sugar, the vinaigrette and some salt and pepper. Mix in the pea shoots and basil leaves and pea shoots. Drizzle with olive oil and taste for seasoning. Transfer the salad to a platter and serve immediately.