Wash, peel and slice the black salsify diagonally and immediately place in vinegar water, drain. Place 1 teaspoon of oil and 1 tablespoon of water in a pot and steam the black salsify for 3-4 minutes.
Peel 3 oranges so that the white skin is completely removed. Remove the fillets with a sharp knife between the parting skins. Clean lamb's lettuce, wash thoroughly and drain. Cut the remaining orange and lime in half and squeeze.
Mix orange and lime juice with 3 tablespoons of oil. Peel and finely dice the onions. Wash the chives and cut into fine rings. Add onions and chives to the orange dressing.
Season with salt and pepper. Heat 1 teaspoon of oil in a coated frying pan and leave diced ham in it. Arrange black salsify, lamb's lettuce and orange filets on a plate, drizzle with the dressing and sprinkle with diced ham.
Cut the bread diagonally in half and serve.