Cut the bacon into fine strips. In a large frying pan, drain and remove until crispy. Wash liver, pat dry and dice. Fry on all sides in the bacon fat. Fry over a low heat for about 5 minutes.
Season with salt and pepper. Deglaze with veal stock. Take liver aside. Wash and quarter apples, remove core. Cut apples into cubes and cook with 1 bay leaf in the stock for about 5 minutes.
Mix sour cream and cornstarch and stir into the stock. Wash the thyme and remove the leaves. Add liver, thyme and bacon to the sauce and bring to the boil briefly. Season to taste with salt and pepper.
Arrange the ragout. Garnish with thyme if desired. Green ribbon noodles taste good with it.