Fry the bacon in a dry frying pan until crispy and set aside. In this fat, brown the bread cubes with the garlic and also set aside.
Add butter, cook onion in it, add celery and carrots and cook. Add all remaining ingredients (except red wine and apple cubes), cover with about 1 to 1.5 l water and bring to a boil.
Boil gently for 20 minutes, skimming off the foam if necessary. If necessary, add a little water.
Add red wine and apple cubes, cook on low heat for another 10 minutes and season with salt and pepper.
Sprinkle bacon and bread cubes over the lentil stew and serve hot.