For the curry sauce, heat a frying pan over a medium heat. Add the spices and dry fry for 2-3 minutes, or until fragrant.
Transfer the fried spices to a mortar and pestle and grind to a powder.
Heat the oil in a frying pan over a medium heat, add two of the onions and fry for 8-10 minutes, or until softened and golden-brown.
Add the garlic and chilli and continue to fry for 2-3 minutes, or until softened.
Add the canned tomatoes, ginger and turmeric and bring the mixture to the boil. Stir in the reserved spices.
Add the stock and simmer the mixture for 25-30 minutes, or until the sauce has thickened and is starting to dry out around the edges. Set the sauce aside to cool slightly.
Using a stick blender, blend the sauce mixture until very smooth. Add the honey and blend again until smooth.
Heat half of the butter in a separate frying pan over a medium heat. When the butter is foaming, add the remaining onions and fry for 8-10 minutes, or until softened and golden-brown. Add the fried onions to the blended curry sauce.
Heat the remaining butter in the frying pan over a medium heat. When the butter is foaming, add the prawns and fry for 4-5 minutes, turning once, or until pink. Add the cooked prawns and the peas to the curry sauce.
To serve, spoon the pilau rice into the centre of six serving plates. Divide the prawn dopiaza equally among the serving plates. Sprinkle over the coriander.