Quarter the endive head, remove the bad leaves and the stalk. Cut off the dark green, outer leaf margins approx. 2 cm wide and discard. Cut the endive into narrow strips and let stand in warm water (with a pinch of salt) for 10-15 minutes (this reduces the bitter taste). Then rinse with cold water.
Peel the garlic, chop up with the garlic press and stir into the sour cream. Add milk and season with salt and pepper.