Crush the Batarekh in a mortar and pestle until it has a smooth texture. Remove the crust from the bread and soak it in milk. Squeeze the milk out of the bread, then mix the bread into the Batarekh, along with the garlic. Grind this mixture with the mortar and pestle until the mixture is smooth. Slowly stir in the lemon juice and then the olive oil, tasting as you go. Add more lemon or more garlic if needed to suit your taste. Serve with thin toast or crackers, along with the black olives. I like a little white feta cheese on the side.