Bring 6 cups water to brisk boil in 3- or 4-quart saucepan. Add salt and peas and cook until crisp-tender, 1 1/2 to 2 minutes depending on size of peas.
Drain peas, shock in ice water, drain again, and pat dry. (Peas can be set aside for up to 1 hour.).
Heat oil over medium heat in medium sauté pan. Add zest and garlic; sauté until garlic is soft but not browned, about 2 minutes. Add peas, lemon juice, and basil; toss to combine. Cook until just heated through, 1 to 1 1/2 minutes. Season with salt and pepper to taste; serve immediately.