Put the chicken in a medium bowl. Mix in the lime juice, paprika, chilli powder and a grinding of black pepper (step 1), then leave to marinate for at least 15 mins, preferably a bit longer.
Heat 1 tbsp of the oil in a large non-stick wok or sauté pan. Tip in the cinnamon stick, cardamom pods, whole chilli and cumin seeds, and stir-fry briefly just to colour and release their fragrance (step 2). Stir in the onion, garlic and ginger and fry over a medium-high heat for 3-4 mins until the onion starts to turn brown. Add the remaining oil, then drop in the chicken and stir-fry for 2-3 mins or until it no longer looks raw. Mix the turmeric, cumin, ground coriander and garam masala together. Tip into the pan, lower the heat to medium and cook for 2 mins (step 3). Pour in the passata and 150ml water, then drop in the chunks of pepper. When starting to bubble, lower the heat and simmer for 15-20 mins or until the chicken is tender.
Stir in the tomato, simmer for 2-3 mins, then add the spinach and turn it over in the pan to just wilt. Season with a little salt. If you want to thin down the sauce, splash in a little more water. Remove the cinnamon stick, chilli and cardamom pods, if you wish, before serving. Scatter with fresh coriander and serve with warm chapatis or basmati rice, if you like.
