These small freshwater crabs are found in great numbers in and around ricefields and flatlands turned into wetlands during the rainy season. Ingredients. Though they do not have much meat, they are caught and fermented in salt water, making a briny crab sauce for seasoning. 1/4 cup rice vinegar (not seasoned) 3 tablespoons sugar; 2 tablespoons water; 4 teaspoons Asian fish sauce; 1/2 teaspoon Salted Crab in Green Papaya Salad (Click on an image to see a larger version.) Add peas and onion and stir to combine. Stir in vinaigrette; season with