To make the chicken curry, heat the vegetable oil over a medium heat, then add the onion, garlic, ginger, chilli and spices and cook for 3 minutes. Add the chicken and chopped tomatoes and 100ml water. Bring to the boil, then reduce to a simmer, cover the pan with a lid and cook for 10 minutes. Remove the lid and cook for a further 5 minutes. Season to taste.
While the curry is cooking, make the saag paneer. Heat 1 tbsp of oil in a large, non-stick frying pan and fry the paneer over medium low heat on all sides until golden. Remove and set aside. Add the remaining oil to the pan and then the spinach. Cook until just wilted, remove to a chopping board and leave to cool slightly, then chop.
Add the onion and garlic to the pan and cook for around 7 minutes, until soft and golden. Add the paneer and chopped spinach back to the pan, along with the garam masala. Heat through for a minute, then set aside.
Make the raita by combining the yoghurt and cucumber in a small bowl with a pinch of salt and pepper.
Serve the curry with the saag paneer and raita.