Place all the marinade ingredients into a baking dish or shallow tray and whisk together. Carefully place the duck breasts in, skin side up, and sprinkle with sea salt. Be careful not to get any marinade on the skin, as this will caramelise too quickly when the skin is cooked. Marinate in the fridge, uncovered, for 2 hours or overnight.

Place all the pancake ingredients into a blender or food processor and blend until smooth. Set aside to rest for 15 minutes before the next step. Place a small frying pan over medium heat and spread a little butter over the surface. Pour around 2 tablespoons of batter in and swirl to cover the base. Cook for 1 minute, until slightly browned, flip, and cook for a further minute. Place on top of a clean tea towel and cover while you repeat the process with the remaining batter.

Remove the duck from the fridge 20 minutes before cooking. Place a pan over medium-low heat. Remove the breasts from the marinade and wipe off any excess. Place the duck skin-side down and sear until golden and crispy, around 7-8 minutes. Flip each breast and sear for a further 1 minute. Place the duck on a baking tray, skin-side up, and bake at 180°C for around 5 minutes. Rest for at least 5 minutes before slicing.

Top each pancake with a little hoisin sauce, a few slices of duck, cucumber, spring onions and a sprinkling of fried onions.