Fish and potato salad are long-time friends – they just get along. In this recipe we're not messing with that chemistry, we're just adding a lovely lemony butter pan sauce and whipping up a dill-heavy dressing to coat those potatoes. It's fresh, it's green, it's good.
Chop potatoes into 3cm pieces. Place potato in a saucepan of cold, salted water and bring to the boil for 10–11 minutes or until tender. Drain and set aside to cool slightly. While potatoes are cooking, continue with step 2.
Finely dice celery. Roughly chop spinach. Finely chop dill.
Zest lemon. Place salt, pepper, butter, lemon zest and ½ the dill in a bowl and mash with a fork to combine.
Place aioli, yoghurt, mustard, remaining dill, ¼ teaspoon salt flakes and black pepper in a bowl and mix to combine.
Brush fish with oil and season with salt and pepper. Heat a frypan over medium-high heat. Add fish, skin-side down, and cook for 5 minutes. Turn and cook for a further 4 minutes or until cooked to your liking. Add lemon butter and cook for 1 minute to brown butter. Remove from heat.
Cut lemon into wedges. Place spinach, celery, potato and dressing in a bowl and mix to combine. Divide salad between plates and top with fish. Drizzle over any pan juices and serve with lemon wedges.