Heat a large fry pan with a medium heat and add in the olive oil, after a couple of minutes, add in the 1/3 cup of chopped onion, mix continuously, after 3 minutes and the onions are lightly sautéed, turn off the heat

Lay the chicken breast over some paper towels and pat dry, then cut each one into 1-inch (2.50 cm) pieces, add them into a food processor (in two batches to not overcrowd), and pulse 10 to 12 times or until the chicken is finely chopped (you can also finely chop the chicken with a sharp knife)

Add the chopped chicken into a large bowl, along with the breadcrumbs, crack in the egg, add in the sauteed onions, including the olive oil in the pan, add in the grated garlic, paprika, chopped parsley, and season generously with salt & pepper, mix together until well mixed

To shape the meatballs, grab a spoonful of the mixture and squeeze it in your hands, this is to ensure all the ingredients are well bound together, then shape it into a ball, about the size of a golf ball, if you see your mixture is too wet to work with, add in some more breadcrumbs, if it's too dry, add in some whisked egg

Heat the same fry pan with a medium heat and add in the 1/4 cup olive oil

After a couple of minutes, add in the chicken meatballs, all in a single layer, and fry for 8 to 10 minutes or until golden fried all around and the chicken is fully cooked through, then remove from the pan and set aside

Using the same pan with the same heat, add in the chopped onion and garlic, mix continuously, after 3 minutes and the ingredients are lightly sautéed, add in the paprika, quickly mix together, then add in the white wine and the bay leaf, mix together and simmer for 3 minutes, then add in the canned tomato sauce and season with salt & pepper, mix together and then simmer

After 3 minutes and the tomato sauce has slightly thickened, add the chicken meatballs back into the pan, once again in a single layer, gently flip each one so they're fully coated in the sauce, and simmer for 1 to 2 minutes or until the meatballs are heated through

Transfer the chicken meatballs and tomato sauce into serving dishes and top off with chopped parsley, enjoy!