Dry fry the cumin, coriander, fennel, and fenugreek seeds for 2-3 minutes until fragrant.
Grind the toasted spices into a fine powder using a mortar and pestle.
Fry two sliced onions in oil for 8-10 minutes until golden-brown.
Add the garlic and chilli and fry for another 2-3 minutes.
Stir in tomatoes, ginger, turmeric, and the ground spices, then bring to a boil.
Add 300ml stock and simmer for 25-30 minutes until the sauce thickens and dries at the edges.
Blend the sauce with a stick blender until smooth, adding honey before blending again.
Fry the remaining three onions in half the butter until golden-brown and add to the sauce.
Fry prawns in the remaining butter for 4-5 minutes until pink, then add prawns and peas to sauce.
Serve the prawn dopiaza over pilau rice and garnish with fresh coriander.