Preheat the oven to 200ºC/Fan 100ºC/Gas 6. Place the chicken thighs and drumsticks in a snug fitting roasting tray. Sprinkle over the chilli and spices and season well with the salt and pepper. Rub the spices and seasoning all over the chicken to coat well. Drizzle over 1 tbsp of vegetable oil. Cover the roasting tray with tin foil and place in the preheated oven for 30 minutes. when time is up, remove the foil and place the roasting tray back in the oven for the skin to crisp up for 10 more minutes.
Meanwhile make the curry sauce. Trim and slice the spring onions and chillies. Finely chop the coriander stalks and pick the leaves into a bowl and place to one side. Peel the ginger and slice into matchsticks. Pick the curry leaves. Slice the cherry tomatoes in half.
In a large saucepan, heat 2 tbsps of vegetable oil. When the pan is hot enough, add the spring onions, 1 of the sliced chillies, the coriander stalks, ginger, curry leaves and mustard seeds. Stir fry for 2 minutes and then add the turmeric. Continue to fry for a minute or two until it starts smelling delicious.
Halve the cherry tomatoes and stir in with a splash of water. Cook for 4 minutes, stirring regularly. Turn the heat down to low, tip in the coconut milk and stir well. Season with salt and pepper, then keep stirring until the sauce has thickened a little. Stir in the spinach and let it wilt.
Once the chicken is cooked, remove the tray from the oven and place the pieces in the sauce. Taste the sauce and season with a little lime juice and salt if needed. Serve with the lime wedges, coriander leaves and rice or bread.