Melt the butter over a medium heat in a high-sided frying pan with a lid or a wide, shallow saucepan with a lid. Once melted, add the onion along with a pinch of salt and fry gently for 5-6 minutes, or until softened. Stir in the curry powder and cook for 1-2 minutes, or until aromatic.
Add the rice and stir to coat in the onion mixture. Season with a pinch of salt and pepper then add the stock and bring to a simmer. Reduce the heat to the lowest setting and cover with a lid. Cook for 12 minutes, or until the rice is tender.
While the rice is cooking boil the eggs. Heat a pan of water and, once boiling, add the eggs and boil for eight minutes. Once boiled, drain and run them under cold water to cool them down. Peel and slice into quarters lengthways.
Bring some water to the boil in a large shallow pan, add the kippers and cook for four minutes until just cooked. Transfer the fish to a plate and set aside until cool enough to handle, then break the flesh into large flakes discarding the bones and skin.
Once the rice is cooked, stir in the defrosted peas and flaked kippers. Cook gently for 3-4 minutes to warm everything through. Taste and season with salt and pepper to taste. Serve with the egg quarters dotted around the kedgeree. Eat hot.