Preheat the oven to 220˚C.
To make the orange alioli, put the orange juice in a pan and reduce to a sticky glaze. Whisk into the alioli and reserve.
Sit the potato on top of a sprinkling of coarse salt on a baking tray and bake until soft and tender. Allow to cool before peeling off the skin. Place the cod in a medium-sized saucepan and cover with the milk. Add the garlic, bay and rosemary. Bring the milk to the boil and then immediately turn off the heat. The fish will continue to cook in the residual heat before cooling down. When cool, flake into small pieces in a bowl.
To make the choux paste, bring the butter and 150ml cold water to the boil in a pan. Add the flour, stirring well until a dough forms and comes away from the sides of the pan. Remove from the heat and let cool for 5 minutes. Slowly add the eggs, beating well to make a smooth, shiny paste.
Add the choux paste, cooked potato, orange juice and seasoning to the cod. Mix thoroughly. Shape into small balls or croqueta shapes. Transfer to the fridge to firm. If you wish, you can freeze them at this stage. Defrost before frying.
Heat the vegetable oil to 180˚C in a deep fat fryer, or until a small piece of bread fizzles when dropped into a deep-sided pan. Fry the fritters until golden brown, cooking in batches so the oil doesn’t cool down too much.
Drain well on kitchen paper and serve with the alioli alongside.
A dry sherry like Fino or Manzanilla would be a good match.