1 Preheat the oven to 200°C. Cook potatoes in a saucepan of boiling water for 5 minutes; drain.
2 Place the potatoes, radishes, capsicums and carrots in a large ovenproof baking dish. Spray with olive oil; cook for 25 minutes, or until the potatoes are lightly golden, turning once.
3 Meanwhile, place the lemon juice and zest, garlic, capers and herbs in a food processor with 3 tablespoons of avocado or olive oil. Blitz the mixture until well combined, adding ¹/³ cup of water to get salsa to a pesto-like consistency. Season to taste; set aside.
4 Spray a large non-stick frying pan with olive oil and set over a medium-high heat. Season the fish with black pepper. Pan-fry for 3–4 minutes, turning once.
5 Divide the fish and roasted vegetables among four serving plates. Drizzle with salsa verde, and serve with extra lemon wedges, herbs and cracked black pepper.