Arrange the chicken in a single layer on a baking sheet. Pat the chicken dry with a paper towel, then season with salt and pepper on both sides.

Pour about 9 oz of the harissa sauce over the chicken. Using your hands or tongs, mix them around until chicken is evenly coated in the sauce. Cover tightly with plastic wrap or remove the chicken to a resealable bag or container and place it in the refrigerator to marinate for 30 minutes to 2 hours.

Pre-heat your grill to 400°. Brush or spray the grill grates with oil to prevent sticking, then add marinated chicken in a single layer. Grill for 6 minutes on the first side, then flip and grill for another 6-7 minutes on the other side or until a thermometer inserted into the thickest part of the chicken thighs reads 165°.

While the chicken cooks, prepare yogurt dip by mixing remaining harissa sauce into Greek yogurt. Add a touch of salt to taste, if desired.