1. Rinse the rice under cold water, then tip it into a small pan. Add a pinch of salt and pour in 150ml boiling water. Pop on a lid, set over a high heat and bring to a boil. Once boiling, turn the heat right down and very gently simmer for 25 mins till all the water has been absorbed. Take the rice off the heat and leave it to steam in the pan, lid on, for 5 mins to just finish cooking the rice.
2. While the rice cooks, make the ponzu dressing. Measure out 1 tsp caster sugar and pop it in a large dish or bowl. Add the tamari and 2 tbsp brown rice vinegar, then squeeze in the juice from the lemon and orange. Stir together till the sugar has dissolved. Taste and add a little more sugar if you think it needs it. Measure out 2 tbsp of the ponzu dressing and set aside in a separate small bowl for later. Add the trout fillets to the remaining ponzu dressing and turn a few times to coat. Leave to marinate while you prepare the veg.
3. Trim the root and top 3cm off the leek. Slice a cross in the top off it and open it out so you can rinse out any dirt. Finely slice the leek.
4. Trim and peel the carrots, then slice them, on the diagonal, into ½cm-thick rounds. Halve or quarter any large shiitake mushrooms. Slice the kale leaves off the thick cores. Discard the cores and finely slice the leaves.
5. Heat your grill to high and line a grill pan or baking tray with foil. Set aside.
6. Warm a wok over a high heat for 2 mins. Add ½ tbsp olive oil, the leek and carrots. Stir fry for 5 mins till the veg start to soften. Add the shiitake mushrooms and kale to the wok. Stir fry for 3 mins till the veg all look juicy.
7. While the veg cook, lift the trout out of the ponzu dressing and lay it on the foil-lined tray, skin-side up. Slide under the grill and cook for 5 mins till the skin is crisp and browned and the trout flesh underneath is dark pink.
8. While the veg cook, lift the trout out of the ponzu dressing and lay it on the foil-lined tray, skin-side up. Slide under the grill and cook for 5 mins till the skin is crisp and browned and the trout flesh underneath is dark pink.
9. While the trout grills, tip the ponzu dressing from the dish into the wok and bubble up. Stir fry for 2-3 mins to finish cooking the veg – they should be tender but with some bite still.
10. The rice should be cooked by now, so fluff it up with a fork and divide between 2 warm plates. Heap on the veg and add a trout fillet to each plate. Spoon the ponzu dressing you saved earlier over the trout and serve straight away.