Clean and wash the chicory, dab dry and cut in half. Wash and pat dry and chop the rosemary, except for something to garnish. Peel and halve the onion and cut into half rings. Wash liver, dab dry and cut into strips. Heat the fat in a pan and fry the liver until golden brown, turning it over. Finally add the onions and fry them.
Season liver with salt and pepper, remove from the pan and keep warm. Briefly fry the chicory halves in hot frying fat, add rosemary and lemon juice and deglaze with stock. Cover and stew for about 5 minutes. Arrange chicory and liver on a plate and garnish with rosemary and lemon. Tastes good with mashed potatoes