Green Sauce is a dish that originates from the Frankfurt/Main (Hesse, Germany) region.
Ingredients (four servings) 
- 3 to 4 cups (200g/7oz each) of sour cream
- 1 tbsp. sunflower oil (or other oil of neutral taste)
- 2 tsp. lemon juice
- 4 hard-boiled eggs
- 10 to 15 large potatoes
- one to one and a half empty sour cream cups filled with dill
- one to one and a half empty sour cream cups filled with other mixed herbs: chives, parsley, onion leaves, lemon balm, burnet, a small amount of sorrel if available
(the amounts of herbs could need more precise measurements; this is all I have)
Mix sour cream, oil and lemon juice and add milk until the mixture takes the consistency of a thick sauce. Chop herbs to very fine bits and mix them into the sauce. Cut hard-boiled eggs to small pieces and add them to the sauce along with some salt and pepper. Leave the sauce in the fridge for about one to one and a half hours.
Boil potatoes and serve hot with the cold sauce. More hard-boiled eggs can also be served along with this.