Flatten the Chicken: Start by placing the boneless chicken thighs in a zip-top bag. Using a meat mallet or a rolling pin, pound them to about ½ inch thick.

Make the Marinade: In a spice grinder, combine the paprika, whole coriander seeds, black peppercorns, dried rosemary, and red chili flakes. Grind them into a semi-coarse blend. In a mixing bowl, whisk together the ground spices with minced garlic, olive oil, lemon juice, and a pinch of coarse sea salt.

Marinate the Chicken: Coat each flattened chicken thigh in the marinade, ensuring they're well covered. Refrigerate for at least 2 hours, ideally overnight.

Build the Vertical Rotisserie: Use half of a large onion as the base for your skewer. Insert the bamboo skewer through the center of the onion half for stability.

Assemble & Roast: Stack the marinated chicken pieces onto the skewer. Preheat your oven to 375°F (190°C) and roast the skewer for about 1 hour or until the chicken is cooked through.

Rest and Slice the Chicken: After cooking, let the chicken rest for about 15 minutes before slicing into thin strips.