The striker admits his finishing came straight from the training ground.
"I've done a lot of work in training with the likes of Bridgey [Marc Bridge-Wilkinson] and Alex [Inglethorpe], we've been doing it on different days. I tried it today and luckily enough it came off for me," he told Liverpoolfc.com post-match.
“It's always good to start the season with a hat-trick and it was a good team performance from the boys, you can't take anything away from that.
“Of course, good to get on the scoresheet and get my first hat-trick."
The 5-0 victory over Stoke represented Liverpool U18s' first taste of competitive action since March 3 – one relished by Stewart and his teammates.
“It's good to get back playing," added the striker.
“Some lads [are] coming in from different countries and they have adapted well, and the players coming up have adapted well to the game. It's very good to get back out there and get some minutes in our legs."