Pardew says the former Marseille midfielder has added a maturity and discipline to his game.
He said: "That goal against Everton was one of the reasons I signed him even though he had suffered a broken leg shortly after.
"I knew it was special. When you have a player who can produce stuff like that, there's going to be more to come.
"I've only ever worked with three or four players, as a manager, with that kind of ability, so I was keen to work with him."