In a bowl, combine chicken, yogurt, lemon juice, turmeric, chili powder, garam masala, ginger garlic paste, and salt.
Mix well and marinate for at least 30 minutes (or overnight for best flavor).
Heat butter and oil in a pan over medium heat. Add onions and sauté until golden brown.
Add ginger garlic paste and sauté for a minute.
Stir in tomato puree, chili powder, garam masala, cumin powder, and salt. Cook until oil separates.
Add marinated chicken and cook until the chicken is fully cooked (10-15 minutes).
Stir in heavy cream and dried fenugreek leaves. Simmer for 5 minutes.
Garnish with cilantro and serve with naan or rice.