Preheat the oven to 190°C.
Mix butter, garlic, parsley, lemon, salt, and pepper in a bowl.
Shape the butter into logs using cling film and chill until firm.
Cut a pocket in each chicken breast and insert half a butter log into each.
Secure the pockets with cocktail sticks.
Prepare three bowls with flour and paprika, beaten eggs, and breadcrumbs.
Dredge each breast in flour, then egg, repeating once, and finally coat in breadcrumbs.
Heat oil in a pan and fry chicken until golden-brown, spooning oil over to seal crumbs.
Transfer chicken to a roasting tin and bake for 10-12 minutes until firm.
Drain on paper, remove cocktail sticks, and serve.