Grease a large pan with 1 teaspoon of oil. Place ##ham## slices smooth inside and fry until crispy on both sides, remove. Cut the rind off the ##bread##.
Dice bread. Take out the ham. Add 2 tablespoons of oil to the pan. Roast the bread cubes in it while turning them golden brown, season with salt and pepper and take them out. Cut the lower stalks off the watercress.
Wash the watercress and drain thoroughly. ##Spinach## wash and drain. Peel and finely chop the onion. Melt the fat in a pot. Fry the onion in it. Add watercress and spinach and fry briefly.
Add stock and ##cream##, bring to the boil and simmer for about 2 minutes. Add horseradish to the stock. Finely puree everything in the stock, season with salt, pepper and sugar. Foam the soup again with a hand blender.
Break the ham into large pieces, serve with the soup and sprinkle with croutons.