1 Steam, boil or microwave the sweet potato for 15 minutes, or until tender. Add the peas for last 3 minutes cooking time. Drain. Transfer to a bowl, and mash the contents roughly with a fork. Set mixture aside to cool.
2 Place the cooled mixture, the salmon, chopped shallots, herbs and lemon zest in a large bowl. Season all with cracked black pepper and stir contents until well combined.
3 Using your hands, divide the mixture into 18 portions and shape into 1.5cm-thick patties. Place the flour on a large plate and season with pepper. Whisk eggs in a shallow bowl. Place breadcrumbs in a separate clean bowl. Press each fishcake into the flour to coat, then dip in the egg mixture and finally coat in the breadcrumbs. Cover, then chill for 30 minutes to firm.
4 Preheat oven to 180°C. Line a large baking tray with baking paper. Place the fishcakes on the prepared tray and spray generously with olive oil. Bake for 30 minutes. Turn fishcakes halfway through the cooking time, or until golden and crisp. Serve with steamed greens and lemon wedges.