Fill a large pot with two quarts of water and 1 tablespoon salt. Bring to a boil.
Cook the peas for 2-3 minutes, then drain them and let them dry on a paper towel. For frozen peas, just rinse and follow directions below.
Melt butter in a medium saucepan over low heat. Turn heat to medium-low. Add scallions and cook for 3 minutes. Add cream, mint, lemon zest, ¼ teaspoon salt, and pepper. Bring mixture to a boil and boil for 30 seconds. Add the peas and cook for another 2 to 3 minutes, stirring well.
Take the pan off the heat and add salt and pepper to taste. Garnish with mint, and serve immediately.