Yogurt tahini sauce

1. In a small bowl, combine yogurt, tahini, lemon juice, olive oil, 1/4 teaspoon kosher salt and pepper to taste.
2. Mixed until well combined. Taste and add more lemon, salt or pepper. Cover and chill until ready.

Grilled chicken skewers:

1. In a large bowl, combine kefir, lemon juice, harissa, garlic, salt, thyme, and pepper. Whisk to combine.
2. Add chicken, toss to coat, and cover tightly with plastic wrap. Refrigerate at least 8 hours and up to 24 hours. Let chicken sit at room temperature for 1 hour before grilling.
3. Preheat grill on high, covered, for 10 minutes then reduce heat to medium. Meanwhile, thread chicken onto metal skewers (about 6 pieces per skewer).
4. Oil grates and grill skewers, turning occasionally, until browned and cooked through or an instant-read thermometer inserted into the center of the chicken registers 165°F, 10- 12 minutes total.
5. Transfer to a platter and serve with yogurt tahini sauce.