Peel and finely dice the onion and garlic. Halve the avocados, remove the stone. Remove the flesh from the skin. Possibly cut off 3 avocado slices for garnishing.
Dice the rest. Puree avocado, onion, garlic, lemon juice and stock. Season to taste with salt, cayenne pepper and paprika. Garnish the dip with avocado slices and parsley if desired