In a large Dutch oven, bring the 8 cups of water to a boil; add peas and cook until crisp-tender, about 30 seconds.
Drain and plunge peas into the ice water bath to stop them from cooking; drain again and slice peas in half diagonally.
In a medium bowl, combine lemon zest and the remaining ingredients with a whisk; add peas and toss gently to coat in sauce.
Radish and Feta variation: Prepare the base recipe, but only use 1/8 teaspoon of the salt. Add 1/2 cup thinly sliced radishes, 1/3 cup crumbled feta (1 1/2 oz), and 3 tablespoons chopped fresh mint or basil to the pea mixture. Adds about 30 calories.
Israeli Couscous and Dill variation: Heat 2 teaspoons olive oil in a saucepan, over medium heat, and saute 2/3 cup Israeli couscous, for 3 minutes. Add 1 cup water, bring to a boil, cover, reduce heat, and simmer 10 minutes. Drain and rinse. Prepare the base recipe with 6 ounces of peas, increase the salt to 1/2 teaspoon and substitute 1/2 teaspoon minced garlic for the shallot. Combine pea mixture, couscous, and 1 tablespoon minced fresh dill. Top with 2 tablespoons shaved Parmesan cheese. Adds about 140 calories.
Toasted Almond and Pecorino variation: Prepare base recipe. Toast 3 tablespoons sliced almonds in a small skillet; cook over medium heat until lightly brown, about 3 minutes. Add almonds to pea mixture, tossing lightly. Top with 3 tablespoons shaved pecorino Romano cheese. Adds about 40 calories.