Wash and clean the cucumber, cut into fine strips and sprinkle with a little salt. Let it stand for about 10 minutes. In the meantime, clean and wash the radishes, also cut into fine strips.
Dice the ham. Wash herbs, chop finely. Peel and chop onion. Puree prepared herbs and onion with half of the buttermilk. Mix the remaining buttermilk, cucumber, radish and ham.
Season with pepper and lemon juice. Chill for about 30 minutes. Roast the toast briefly in the toaster and cut into rhombs. Serve with cold skin. Serve garnished with fresh herbs.