To make the pastry, place all the ingredients into a kitchen aid mixer with a paddle attachment and mix for 5mins until it forms a smooth dough. Wrap in cling film and rest in the fridge for 1 hour.
To make the filling, add half of the olive oil into a saucepan, add the chopped onion, crushed garlic, season, cover with a lid and sweat for 15mins. Once it is soft, drain the onions in a colander.
Add the remaining olive oil into a frying pan and sweat the chopped Swiss chard stalks for 5mins, season and add to the onions.
Add the Swiss chard and onion into a large bowl, add all the remaining ingredients and season with salt and pepper.
Take the dough out of the fridge, cut in half and using a pasta machine, roll out to the thinnest setting. Spoon a teaspoon of mix along the length of the rolled dough, leaving a gap of 3cm between each spoon of mix. Using a pastry brush, very lightly wet the dough around the filling then fold the dough in half and seal together making sure that there are no air pockets. Take a round cutter and cut the Barbajuans into half moon shapes.
Deep fry at 190C for 3mins or until golden brown and crispy. Place on a plate and grate some parmesan over the top and serve.