Add the chicken and the ingredients for the marinade in a bowl. Massage yogurt mixture into chicken until well coated. Set aside while you prepare the ingredients for the sauce. You can also prepare the chicken beforehand and marinate it up to 3 hours in the fridge.
Heat oil in a large skillet over medium-high heat. Working in 2 batches, cook the chicken, stirring occasionally, until browned all over, 5 minutes per batch. Transfer chicken to a plate.
Reduce heat to medium-low. Melt 1 tbsp butter. Add garlic, onion and ginger. Cook until soft, 3 minutes. Add garam masala and chili powder. Stir in tomato paste and red curry paste. Cook for 2 minutes.
Add coconut milk and bring to a boil. Season with salt and pepper. Return chicken along with any juices to the skillet together with 1 tbsp butter and lime juice. Bring to a simmer and cook until chicken is just cooked through, 10 minutes. If the sauce thickens too much, add a splash of water.
In the meantime, boil the rice and prepare naan.
Serve the chicken with rice and naan. Top with scallions, chili flakes and pistachios. Enjoy!
