Using a mortar and pestle, crush the garlic cloves with the salt into a paste.
In bowl of food processor, add crushed garlic, lemon juice, cumin, and tahini.
Process until the mixture emulsifies and thickens.
Stream in ice water, a little at a time, while the motor is running. Process until the mixture is creamy and lightens in color.
Store in refrigerator in airtight container.