These skewers get a nice, long marinating time due to the low amount of lemon juice. If your marinade is loaded with vinegar or citrus, go for 30 minutes to an hour at most to ensure the best texture.
How to Make It
Microwave 2 cups water in a microwave-safe 1-quart measuring cup on high 3 minutes. Submerge chile in hot water. Let stand until soft and pliable, about 10 minutes. Drain; stem and seed chile.
Combine chile, onion, 2 tablespoons oil, harissa, lemon juice, and salt in a blender. Process until smooth and creamy, about 20 seconds. If needed, add 1 tablespoon water to thin.
Using a silicone spatula, scrape marinade into a gallon-size ziplock plastic bag. Add chicken, and stir to coat well. Seal and chill 4 hours or up to 18 hours.
Thread chicken onto 4 (8- to 12-inch) skewers (keep chunks close to one another, forming a column of meat, to ensure juicy results); bring to room temperature, about 1 hour.
Prepare a hot fire in a charcoal grill or preheat a gas grill to high (450°F to 500°F). Alternatively, heat a lightly oiled grill pan over high. Gently blot excess marinade from chicken to ensure a nice sear. Brush chicken with remaining 1 tablespoon oil.
Grill skewers, turning every 2 minutes, until chicken is lightly charred and cooked through, about 14 minutes. Let rest 5 to 10 minutes. Garnish with chives, if desired.