Finely chop the onion.
Add the olive oil to a frying pan and cook the onion until they are soft and starting to color.
Place the cooked chicken into a food processor, along with the breadcrumbs, salt, pepper, and sage.
Blitz until everything is chopped. Add the onion mixture and pulse again.
Check your seasoning. It might need more salt.
Once you are happy with the flavor, crack in the egg and then whizz until you have a thick paste.
Fill a shallow bowl with a little water. Wet your fingers and take a teaspoon of the mixture. Roll it to form a ball and set aside on a plate.
Repeat until all of the mixture has gone (approximately 20 balls).
Tip the panko breadcrumbs into a small bowl and carefully add a chicken ball, juggle the bowl about, rolling the ball until it is well coated.
Place it back on the plate and coat all of the croquettes.
Deep fry at 350°F/175°C for around 3 minutes until golden brown.
Drain on kitchen paper before serving.
Add about a tablespoon of oil to a pan and cook them over a relatively high heat. Then add more oil and turn the croquettes.
Drain on kitchen paper before serving.
