In a bowl, combine plain yoghurt, lemon juice, garam masala, ground cumin, cayenne pepper, curry powder, black pepper, salt, grated garlic and ginger.
Cut chicken into bite size pieces and add it to the bowl with the marinate. Cover all the chicken pieces with the marinate and let marinate in the fridge for about 4 - 24 h.
Melt some butter in a pan over high heat.
Add the chicken to the pan and cook for about 5 min.
Add the tomato passata, cream, plain yoghurt and sugar, stir and let simmer for about 20 min.