Ingredients: For the Marinade: 500g boneless, skinless chicken thighs or breasts, cut into bite-sized pieces 1 cup plain yogurt 2 tablespoons ginger-garlic paste 1 tablespoon lemon juice 1 teaspoon ground turmeric 1 teaspoon ground cumin 1 teaspoon ground coriander 1/2 teaspoon red chili powder Salt to taste For the Sauce: 3 tablespoons butter 1 tablespoon oil 2 onions, finely chopped 2 tomatoes, pureed