To make the Pickled Cauliflower, combine white wine vinegar, sugar, salt, dill and 400ml of water in a medium saucepan and bring to the boil. Transfer to a heatproof bowl and place over an ice bath. Add sliced cauliflower and set aside.
To make the Roasted Cauliflower, line a baking tray with baking paper. Spread hazelnuts onto tray and bake for 5-7 minutes. Remove from oven and place into a clean tea towel, fold towel over and rub to remove skin. Place into a mortar and pestle and set aside.
Meanwhile, place a small frypan over medium heat. Toast off coriander and fennel seeds, about 1-2 minutes and add to hazelnuts in mortar and pestle. Grind to a coarse crumb and place into a large bowl with oil, sesame seeds and cauliflower florets. Toss to coat and place on a baking tray. Roast in oven until golden and just crisp, about 20 minutes. Set aside.
To make the Pea Puree, place peas, fennel and 1 litre of water in a medium saucepan and bring to the boil. Reduce heat and simmer for 15 minutes. Strain peas, reserving cooking water, place into a blender and blitz until smooth. Adjust to taste by gradually adding butter and a little cooking water. Season to taste and set aside, keeping warm.
To make the Parsley Oil, bring a small pot of water to the boil. Blanch parsley in water for 1 minute, remove and squeeze dry with paper towel. Place parsley leaves into a blender with oil and blend on high until smooth, about 2 minutes. Pour parsley oil into a sieve lined with muslin cloth over a bowl and set aside in fridge to drip through.
To make the Herb Salad, bring a small saucepan of water to the boil. Cut tips off asparagus and reserve. Use a potato peeler to peel strips of asparagus and place into iced water. Add peas and asparagus tips to boiling water, blanch for 10 seconds then plunge into iced water with asparagus strips. Drain off greens from iced water, and add to a bowl with watercress leaves, micro cress, micro chervil, micro parsley and tendrils. Set aside.
To make the Dressing, whisk all ingredients with 40ml water in a small bowl until combined. Pour over herb salad, season and gently toss to coat, season and set aside.
To cook the Barramundi, heat 1 tablespoon oil in a frypan over medium heat. Add fish, skin side down, and press down for 30 seconds to prevent curling. Once fillet is cooked halfway, flip fillet and add butter and thyme. Cook for a further 2 minutes and remove from pan. Set aside to rest.
To cook the Scampi tails, melt butter in a small saucepan to 60C. Add scampi and poach until cooked, about 2 ½ minutes. Remove from pan and set aside, keeping warm.
To serve, finish pea puree by whisking through 1tbsp of butter. Place a dollop of pea puree onto plate, top with scampi. Layer some pieces of cauliflower on top of scampi and place fillet on top. Add some dill and pickled cauliflower. Spoon some salad next to fillet and finish with bean flowers and drizzle some parsley oil around plate.