Over medium heat, cook the chopped leeks in oil for 5 minutes. Add cilantro and mint and cook for 1 minute more.
Remove the pan from the heat and whisk in the yogurt. Season with salt and pepper and add lemon juice if desired. Serve warm at once or refrigerate and serve cold.
Makes: 1 1/2 cups
Can be used as a dip for cold fish, poultry or raw vegetables.