Peel the onions. Wash, clean, peel and core the cucumbers. Cut onions and cucumbers into very small cubes. Mix prepared ingredients, vinegar, sugar, mustard seeds and salt in a saucepan, season with pepper. Simmer at high heat for about 12 minutes
Wash the dill, shake dry. Pluck the pennant and chop finely. Add about 3 minutes before the end of cooking time and cook at the same time. Pour the dill while still hot into carefully prepared glasses (preferably with twist-off lids), close well and store in a cool place.