In a large pan over medium heat, bring 2 quarts of water to a boil.
Add fresh peas and simmer 2 to 3 minutes until tender. Drain and set aside. If using frozen peas, just rinse and follow directions below.
In a medium saucepan, melt butter over low heat. Increase heat to medium-low and sauté scallions for 3 minutes until soft. Stir in cream, mint, and lemon zest. Bring to low boil, lower heat to low. Add peas and simmer, while stirring, for 2 to 3 minutes. Season with salt and pepper.
Serve garnished with mint leaves.