Heat the oil in a large saucepan over a medium heat, add the onion and a big pinch of salt. Gently fry until the onion is translucent, so around 10 mins, then add the garlic and spices.
Stir and cook for another minute, adding a splash of water to prevent them sticking. Tip in the coconut milk and stir well, then simmer for 10 mins.
Tip the chopped cod or salmon pieces and the frozen peas into the pan. Cook until the peas are bright green and the fish starts to flake – around 3 mins. Season and add lime juice to taste. Ladle into bowls. Serve with yogurt and cauliflower rice.
