The German hit a hat trick at Craven Cottage as the Blues maintain their four-point lead at the top of the Premier League.
Schurrle broke the deadlock early in the second half and found the net twice more inside 16 minutes to settle the west London derby in the visitors' favor.
Mourinho described the 23-year-old as "cool" in front of goal and was delighted to see his team secure victory after a drab first half at Craven Cottage.
"Schurrle's in a learning process in the Premier League but he has cold blood, in front of goal he is cool," he said.
"He's a good finisher and that's what I expect from him.
"This was a real game of two halves, the first half was very poor and the second was brilliant, it was a great three points for us.
"I decided not to speak at halftime because I would have needed more than 10 minutes, but the players showed they are intelligent."
Chelsea is four points clear at the top of the Premier League table with 10 games remaining, though third-placed Manchester City is six points behind with two games in hand.
And Mourinho still believes that Manuel Pellegrini's side is the favorite for the title.
"We have four points more than Arsenal," he said. "But if City win their two matches in hand they are top of the league. For me I am not top of the league, I am only there occasionally."