TARRATTOR - COLD YOGURT SOUP

1 lb. plain yogurt
1 1/2 cups cold water
1 peeled and finely chopped cucumber
2 cloves garlic, pound up
4 tbsp vegetable or olive oil
1 tsp salt
2 tbsp fresh dill
1/2 finely chopped walnuts (optional)
In a large bowl mix yogurt and water until smooth. Add all other ingredients, stir well. Serve. Makes 6-8 servings. In hot summer days you can add 1 cube ice in each serving bowl.