Half fill a medium pan with water, add the stock cube and bring to the boil. Stir in the rice and return to the boil. Cook for 10 minutes, or according to pack instructions, until tender.
Preheat the grill. Place the cod on a foil-lined baking tray and spread each fillet with mango chutney. Sprinkle with the cumin seeds, chilli flakes and plenty of pepper. Cook under a medium-hot grill for 7-10 minutes, until cooked through.
Meanwhile, melt the butter in a large pan and cook the onions, garlic and peppers for 8-10 minutes. Add the peas, turmeric, curry powder and lemon zest and cook for another 2 minutes, stirring constantly.
Drain the rice and then tip it into the pan with the vegetables. Scatter over the spinach and toss together over a low heat until the spinach wilts. Divide the rice between four plates and top each with a fish fillet. Spoon the yogurt or soured cream on top and garnish with a wedge of lemon or lime and fresh herbs.