This simple sauce is a basic building blocks and is so versatile that once you master it, there are a million things you can do with it. The important step here is to allow the garlic and lemon juice to hang out for 10 minutes after blending but before adding the jarred tehina. This step helps stabilize the garlic and prevents it from fermenting and turning sour and aggressive, which is the problem with a lot of tehina sauces (and therefore the hummus made from them). Because you're making an emulsion (oil-based tehina incorporated into water and lemon juice), the tehina sauce can sometimes separate or seize up. Don't panic! Keep a glass of ice water nearby and add a few tablespoons at a time to the lemon juice-tehina mixture while you're whisking, until your creamy emulsion returns.