Fill your kettle and boil it. Add 1 level tbsp miso to a heatproof jug or bowl Peel and grate the garlic and ginger into the jug. Pour in 200ml boiling water from the kettle and stir to mix.

Rinse the rice under cold water and then tip it into a small pan. Pour in 300ml boiling water and add a pinch of salt. Cover, bring to the boil, then turn the heat right down and simmer for 8 mins till the rice has absorbed all the water. Take the pan off the heat and leave the rice in the pan, lid on, to steam in the pan for 3-5 mins.

Meanwhile, tear the mushrooms into small pieces. Put a deep frying pan or wok on a medium heat and add ½ tbsp oil. Add the mushrooms and fry them for 3 mins, stirring, till starting to turn golden. Stir in the baby leaf spinach and cook, stirring for 2 mins to just wilt the spinach.

Pour the miso stock into the pan. Lower the cod fillets into the pan, skin-side down. Pop a lid on the pan (or use a baking tray if you don't have a lid). Simmer the cod for 5-6 mins till it is cooked through. The cod will be white, opaque and flake easily when pressed with a fork.

Taste the miso broth and add a pinch of salt or pepper if you think it needs it. Fluff the rice with a fork and divide it between 2 warm plates or bowls. Top with the cod, veg and miso broth to serve.