Dressing is best with fresh ingredients. I use fresh thyme in this recipe but other herbs would work well too, such as dill, marjoram, or oregano.
The key to keeping yogurt-based dressing thick and creamy is to not overwork the yogurt. Excessive whisking only causes yogurt to thin out. For that reason we are going to start with the mayo part, mix everything in and then work in the yogurt.
In a large mixing bowl, add the 1/2 cup of mayonnaise, 2 cloves of minced garlic, 1/2 teaspoon of fresh lemon juice, 1/2 teaspoon of chopped thyme, 1/4 teaspoon of sugar, 1 teaspoon of Dijon mustard, and 1/2 teaspoon of sea salt. Mix well, adding more salt and some fresh cracked pepper as needed.
Now let's mix in the 1/2 cup of Greek yogurt, being careful to not over mix.
Add in the tablespoon of buttermilk, using more depending on whether you are using this for dressing or as a dip.