For the marinated chicken, combine the chicken with the lemon juice, red chili powder, paprika and salt. Mix well. Add the yoghurt, ginger, garlic, garam masala and oil. Mix until combined. Let it marinate for 30 minutes.
Heat a frying pan over high heat. When the pan is very hot, add the chicken. Cook for 3-4 minutes or until starting to char and burn at the edges. Turn over the chicken and cook for a further 3-4 minutes or until starting to char and burn at the edges. Don’t worry about cooking the chicken all the way through, as it'll cook through in the sauce later. Transfer to a plate and set aside for later.
While the chicken is cooking, heat butter in a deep frying pan over medium-high heat. When the butter is foaming, add the cardamom and cinnamon. Cook for a minute or until fragrant. Then add the ginger and garlic. Cook for another minute. Add the tomato paste, paprika, erythritol and salt. Simmer for 10 minutes, stirring every so often.
Add chicken to the sauce. Simmer for 10 minutes. Then stir through the cream. To serve, drizzle over the yoghurt and sprinkle with fresh cilantro leaves. Enjoy!