Combine the garlic and lemon juice in a medium bowl. Let it sit for 1 to 2 minutes. 

Whisk the tahini, turmeric, cumin, and coriander into the garlic mixture until just combined. Don’t worry if it gets thick and grainy. Whisk in the water, ¼ cup at a time, until the sauce is smooth and creamy. It should be the consistency of a creamy salad dressing, like ranch. 

Store in a closed container in the refrigerator for up to 3 days.