Chicken Tikka masala recipe

600g/ 1.2lb chicken thigh (boneless, skinless), cut into 3cm / 2.2" cubes (Note 1) ▢1/2 cup plain yoghurt, full fat best (Greek is fine) ▢6 cloves garlic , minced (~1.5 tbsp) ▢1 tbsp fresh ginger , grated ▢1 tsp garam masala (Note 2) ▢1 tsp each salt, cumin, ground coriander, paprika (sweet, normal or smokey) ▢1 tbsp vegetable oil ▢1/8 tsp cayenne pepper (optional) ▢Pinch black pepper ▢2 tsp lemon juice Cooking Chicken: ▢1 - 2 tbsp oil (Note 3) Curry Sauce Spices: ▢2 tsp turmeric ▢1 tbsp garam masala (Note 2) ▢2 tsp coriander ▢1 tsp cumin ▢1/8 tsp cardamom powder ▢1/8 tsp cayenne pepper Curry Sauce: