Marinate the chicken. In a bowl, mix the yogurt, lemon juice, 1 tsp salt, 1 tsp garam masala, and 1⁄2 tsp turmeric. Add the chicken pieces and toss to coat. Let it sit for at least 20 minutes (or up to 4 hours in the fridge).
Cook the chicken. Heat 1 tbsp butter in a skillet over medium-high heat. Remove excess marinade from the chicken and cook in batches until lightly browned (3-4 minutes per side). Set aside.
Make the sauce. In the same skillet, add 3 tbsp butter, onions, garlic, and ginger. Cook until onions are golden (5-7 minutes). Stir in garam masala, cumin, smoked paprika, and remaining turmeric. Cook for 1 minute to toast the spices.
Add crushed tomatoes and simmer. Let the mixture bubble gently for 10 minutes, stirring occasionally. Blend using an immersion blender for a smoother sauce.
Finish the dish. Stir in the heavy cream, honey, and cooked chicken. Simmer for 8-10 minutes until the chicken is fully cooked and the sauce thickens. Taste and adjust salt or honey as needed.
Warm the naan. Heat a dry skillet over medium heat or warm naan in the oven at 350°F for 3-5 minutes. Brush with melted butter.