Place the broad beans in a large saucepan of water and boil for 3 minutes. Drain, then rinse under cold, running water.
Add the mint, courgettes and lemon zest to the beans and lightly season. Gently fold through the watercress.
Place the flour onto a large plate and season with salt and pepper. Pat the fish fillets dry with a kitchen towel then coat in the flour.
Heat 1 tbsp of oil in a large frying pan, place over a medium-high heat and cook the fish skin-side down for 4 minutes. Then turn the fish over and cook for a further 3 minutes, until the skin is crisp and the flesh is opaque and flakes easily.
In a small bowl, combine the remaining 1 tbsp olive oil, half the lemon juice, the white wine vinegar and the pesto. Serve the fish with the salad, and drizzle over the pesto dressing. Serve immediately.
