Prepare the chicken: Remove the skin from the whole chicken. Use a knife to loosen skin around the wings if needed. Cut the chicken at the breast and back to allow marinade penetration and reduce cooking time.
Initial marinade: In a bowl, combine salt and freshly squeezed lemon juice. Massage this mixture thoroughly into the chicken to tenderize and flavor it. Refrigerate for 20 minutes.
Prepare tandoori marinade: In a blender, puree fresh ginger, garlic, olive oil, and yogurt until smooth. Add ground coriander, chili flakes, paprika, garam masala, tandoori masala, turmeric, salt, cumin, and fenugreek seeds. Blend again to form a fine spiced paste.
Marinate chicken with tandoori paste: Remove chicken from fridge. Massage the tandoori marinade thoroughly into and onto the chicken, especially into the cuts. Coat the chicken completely. Cover and refrigerate for at least 3 hours, preferably overnight.
Bring chicken to room temperature: Remove chicken from fridge and let it rest on the kitchen counter for 30 to 45 minutes before cooking.
Preheat oven: Preheat the oven to 220°C (428°F) with hot air (convection).
Roast the chicken: Place the chicken breast side down in a baking dish. Roast for 15 minutes, then turn breast side up and roast for another 15 minutes. Turn again breast side down and roast for a final 15 minutes. Total roasting time approximately 45 minutes.
Rest the chicken: Remove chicken from oven and let it rest for about 10 to 15 minutes before serving.
Serve: Serve the tandoori chicken with naan bread, rice, or fresh raita. Optionally garnish with fresh coriander and chili.