For the Pickled Fennel, place the apple cider vinegar, sugar, salt, ground fennel and ¼ cup of water into a small saucepan over high heat and bring to the boil. Remove from the heat and allow to cool slightly. Place the thinly sliced fennel into a small bowl then cover with pickling liquid and set aside.
For the Brown Butter Emulsion, place the butter into a small saucepan over medium heat and cook until butter turns a nut-brown colour, careful not to burn, about 8-10 minutes. Strain through a fine sieve and discard the brown milk solids. Transfer the strained liquid to a pouring jug and set aside to cool to room temperature.
Bring a small saucepan of water to the boil over medium heat, add the egg and boil for 2 minutes to coddle. Remove egg and place into an ice bath for 5 minutes.
Remove from the ice bath and crack the egg carefully into a stick blender canister. Use the egg shell to remove any hardened egg white. Add the apple cider vinegar, salt and pepper. Blend with a stick blender to combine. While blending, slowly pour in the cooled browned butter liquid and blend until emulsified. Season to taste and set aside.
For the Charred Baby Cos Hearts, heat a large frypan over high heat. Cut the lettuce hearts in half, lengthways, and brush the cut sides with olive oil. Add the cos halves, cut side down, to the hot frying pan and cook until charred, about 3-4 minutes. Remove from the pan, season with salt and set aside.
For the Crispy Capers, heat the oil in a small saucepan over a medium heat. Add the capers and fry until crisp and golden, about 5-6 minutes. Remove from the oil and set aside on paper towel.
For the Soft Boiled Eggs, bring a small saucepan of water to the boil over a high heat. Add eggs and boil on a medium heat for 5 ½ minutes. Remove the eggs and place into an ice bath for 5 minutes. Peel then season with salt and set aside.
For the Seared Tuna, place a large frypan over high heat then add oil. Trim tuna into even sized portions and coat in ground fennel and salt. Once the frypan is very hot, add the tuna and sear for 1 minute on each side, or to your liking. Remove from the pan and rest for 5 minutes. Cut into 1cm thick slices.
To serve, cut the Soft Boiled Eggs in half and arrange over plates with drained Pickled Fennel, Charred Baby Cos Hearts, Crispy Capers and Seared Tuna slices. Dress with Brown Butter Emulsion and garnish with fennel fronds and flowers.