Sautée green peas in vegetable oil over medium heat until almost tender. This takes between 5-10 minutes depending on the type of your green peas and whether you use frozen or fresh peas. Skip this step if using canned peas.
Add chopped parsley, salt, sugar and flour. Stir and let it cook for another minute.
Pour water then milk, stir. Cook for 3-4 minutes over low heat, stirring occasionally.