Remove roasted garlic from oven and squeeze out cloves.
Add lemon juice, tahini and roasted garlic. Transfer mixture to a food processor or blender. The mixture will appear very liquid. Puree until smooth.
Using a fine wired mesh strainer, strain mixture into a separate bowl. It is best to use a rubber spatula or the back of a wooden spoon to press mixture through. Discard the solids.
Press the mixture through a sieve until only solids remain. Discard.
Stir in shredded parmesan and season with pepper to taste.