In a bowl, mix yogurt, lemon juice, half the garlic, half the ginger, 1 tsp garam masala, chili powder, turmeric, and salt. Add chicken pieces and marinate for at least 1 hour (or overnight).
- In a large skillet, melt 1 tbsp butter over medium heat. Add marinated chicken and cook until browned and cooked through. Remove and set aside.
- In the same skillet, add remaining butter, garlic, and ginger. Sauté until fragrant. Stir in tomato puree, remaining garam masala, salt, and sugar. Simmer for 10 minutes.
- Reduce heat and stir in heavy cream. Add the cooked chicken back into the sauce. Simmer for 10–15 minutes until the sauce is thick and creamy. Adjust seasoning.
- While the butter chicken simmers, cook fries according to package directions or fry until golden and crispy. Season with salt immediately after cooking.
- Warm garlic naan in a skillet or oven. Optional: brush with olive oil or melted butter and minced garlic before warming.
- To serve, plate butter chicken with crispy fries and warm garlic naan. Garnish with fresh cilantro and serve hot.