Wash and clean the salad. Pluck romaine lettuce into pieces. Peel 3 blood oranges so that the white skin is completely removed. Remove the fillets with a sharp knife between the parting skins.
Halve 1 blood orange, squeeze juice. Mix juice and mustard well, season with salt, pepper and sugar. Fold in 2 tablespoons of oil drop by drop. Roast sunflower seeds in a pan without fat, remove.
Clean and halve the mushrooms. Heat 2 tablespoons of oil in a frying pan, add the mushrooms and fry them for 3-4 minutes while turning them, remove them and season with salt and pepper. Carefully mix salad, mushrooms, orange fillets and vinaigrette and arrange on plates.
Place the ham on top as a roll and sprinkle with sunflower seeds.