The Denizens of the Stars' "starship creation technique" was a wondrous work of technology. And truth be told, Hao Ren was not even sure if such abstract stuff could be categorized as "technology", but considering that magic or technology led to the same end goal in the search for truth, Hao Ren decided to take it for what it was: technology.
The core of this technology was based on "expansion of the mental frame" and solidification of materials.
The Denizens of the Stars were some of the most ancient intelligent beings in that universe. They were born among the ruins of stars, and in that dark, chaotic age under the tyranny of the Mad Lord, these intelligent beings had no place to call home. They found their "materials" in every ruin, wreckage, and dead planet, and their technology revolved as well as grew around the dearth of resources.