Ingredients
60g butter
1 small onion, very finely diced (about 60g)
150g plain flour, 70g for the béchamel and the rest for the egg wash
450 ml full-fat milk
3 tbsps sour cream
200g 50:50 crab meat
¼ tsp salt
¼ tsp ground white pepper
½ tsp shichimi togarashi or a small pinch of chilli powder
1 egg, beaten
250g panko breadcrumbs
Flavourless oil, for deep-frying — about 1 litre

Method
Melt the butter in a saucepan over a medium heat and cook the onion for 5-7 minutes until the onion is soft and translucent.  When the onion is soft, beat in the flour and cook for a minute or two stirring the whole time. Take off of the heat and add the milk slowly, mixing all of the time until the milk has all been added.  Cook for 5 minutes until thick and glossy. 

Add the sour cream to the béchamel and stir. Stir in the crab meat, salt, pepper and shichimi togarashi and check the seasoning.  Keep cooking the sauce, stirring frequently, until very thick, about 10 minutes. Pour into a container, cover with cling film directly on the surface to stop a skin forming and put into the fridge and leave to cool for at least an hour. 20 minutes before you start cooking, put into your freezer to completely chill.

When the filling is totally cold and set get an ice cream scoop and scoop a level scoopful, straight into your flour. Completely coat your ball with flour then put into the beaten egg, then roll them in the breadcrumbs ensuring they are completely coated.

Preheat the oven to 180c and put a baking tray into the oven.

Place your croquettes on a tray and put back into the fridge for 15-20 minutes to firm up again before frying.

Pour your oil into a wok to come no higher than halfway up the sides and heat the oil on medium to 180c. 

Carefully put the croquettes into the hot oil 4 at a time and fry until the crust is golden brown (around 5 minutes). Remove the croquettes with a slotted spoon and drain on kitchen paper. Turn off the oven and place the first batch into the oven to keep warm while you finish off frying the croquettes.

Scatter the chives over the top and serve immediately.