Sugar Snap Pea Soda

On a recent trip to Nitehawk Cinemas I ordered their "Summertime Cooler" which lists "sugar snap pea, lemon, elderflower, soda" as it's ingredients. I can't find a photo of Nitehawk's drink, but it was basically a N/A snap pea hugo spritz OR a snap pea elderflower soda, depending on how you want to look at it. It was GREEN and it was ever so slightly vegetal and it was GREAT! I want to make snap pea syrup now! If you have a good recipe hmu