The slightly salty and herbal flavour of native saltbush makes a perfect partner to delicate fish and sweet leeks in this classically creamy fish pie. There's no pastry here, rather, the pie is topped with a golden mash for spoonfuls of warming comfort.
Peel potatoes and cut into 2cm pieces. Place in a saucepan of cold, salted water over high heat and bring to the boil. Cook for 15 minutes or until tender. While potato is cooking, continue with step 2.
Cut green top from leek and discard. Halve leek lengthwise, rinse under cold water and finely slice. Finely chop cauliflower. Melt ½ the butter in an ovenproof frypan over medium-low heat. Add leek with 1⁄4 teaspoon salt flakes and cook, stirring, for 12 minutes or until softened.
Meanwhile, drain potatoes and return to saucepan with remaining butter, milk and saltbush. Use a potato masher to roughly mash. Set aside and keep warm.
Add cauliflower to pan with leek and cook, stirring occasionally, for 5 minutes or until slightly softened. Preheat overhead grill to medium.
Cut fish into 3cm pieces. Place in a bowl with flour and toss to coat. Finely chop dill. Finely zest lemon and cut into wedges. Add fish, dill, zest and sour cream to the pan, gently stir to combine and bring to a gentle simmer. Cook for 6 minutes or until fish is almost cooked through. Season to taste with salt and pepper.
Spoon mashed potato over fish mixture. Place frypan on a shallow tray under the preheated grill and cook for 8–10 minutes or until golden and bubbling (the tray will catch any juices that bubble over the top). Serve fish pie with salad leaves and lemon wedges.