Heat 1/2 cup of water in a microwave safe glass for 1 minute. Get a bowl large enough to hold all the ingredients. Add the water, peanut butter, curry paste, vinegar, juice of half a lime, cilantro and 1/2 teaspoon of salt. Whisk this vigorously until it is well combined. Add the cucumber and the zoodles and toss in the sauce, Top with the green onion and red pepper flakes