Zaatar is a Middle Eastern spice mix that includes sesame seeds, sumac, dried thyme, and dried marjoram. Its available at specialty foods stores and Middle Eastern markets and from adrianascaravan.com.
Ingredients
1 large garlic clove, peeled
1 cup mayonnaise
4 teaspoons fresh lemon juice
1/4 cup extra-virgin olive oil
1/4 cup za'atar
Directions
With machine running, drop garlic through feed tube of processor and chop finely. Add mayonnaise and lemon juice. With machine running, drizzle in oil in thin stream, blending until smooth. Transfer to small bowl. Whisk in za'atar and season with salt and pepper. Let stand at least 30 minutes to allow flavors to develop. DO AHEAD: Can be made 1 day ahead. Cover and chill. Bring to room temperature before using.