First make the soup. Sauté the onions in butter until they are soft and translucent. Add the potatoes, celery and thyme and continue to simmer for about 5-10 minutes and then pour in the chicken stock and the cream and bring to just under the boil and simmer for about 10-15 minutes. Stir in the smoked fish and simmer until all the flavours infuse. Remove the thyme and pour the soup into a food processor and blend until smooth.
Next make the marinade for the cucumber. Place the vinegar, oil, apple syrup and mustard in a bowl and whisk until it emulsifies. Slice the cucumber very thingy (use a mandolin for this if you have one) and coat the cucumber with the dressing and leave to marinate in the fridge.
Lastly dust the fillets of unsmoked trout in the flour and pan fry in butter and sunflower oil over a high heat. Cook both sides quickly until golden and then remove form the heat and drain on some kitchen paper. Squeeze a little lime juice over the trout.
To serve, place the cooked trout on the plate. Put some cucumber pickle alongside with a piece of cold unsmoked trout on top. Pour some hot trout soup into a shot glass and put on the plate and garnish with a wedge of lemon.