In a pan, drizzle a little bit olive oil and saute the minced onion.
Add garlic and saute as well.
Add the shredded chicken breast and saute for a few minutes.
Add tomato paste, season with salt and black pepper.
Finish with minced parsley and set it aside.
Pour the water used to cook the chicken in a pan and add milk and butter.
Season with salt..
When the butter melts, add all at once the flour and stir with a wooden spoon.
Cook over low heat for 10-15 minutes or until the dough becomes smooth and doesn't stick to the bottom of the pan.
Transfer the dough to a cold surface and flatten it with a spatula.
Cover with plastic wrap.
When the heat subsides and it's possible to touch the dough, knead until smooth..
When the filling and the dough are cold, mold the chicken breasts: take a handful of dough and mold it like a seashell.
Add 1 tablespoon of the chicken and requeijão mix.
Close the dough pressing hard with the fingers and remove any excess.
Cover the chicken breast with the beaten egg whites and then with the breadcrumbs.
Fry in hot oil until golden.