Poached ocean trout and potato with herb mayo

Ingredients

• Herb mayonnaise
• 1 cup flat leaf parsley
• 1/2 cup basil
• 200 millilitre rice bran oil
• 2 egg yolks
• 1 teaspoon dijon mustard
• 1 teaspoon white wine vinegar
• 4 kipfler potatoes
• 1/2 onion, chopped
• 1 small bay leaf
• 4 black peppercorns
• juice of 1/2 lemon
• 2 200 g ocean trout fillets, skin on
• 2 green onions (shallots), sliced diagonally
• 4 tomatoes , sliced
• lemon wedges, to serve