He said to me, How do you feel about improv?
So we improvised the scene, and he was obviously rooting for me to get the job.
The entire production was awesome.

‘Harold & Kumar Go to White Castle’ producer Nathan Kahane explains how Ryan Reynolds helped get the movie made.New Line Cinema/Courtesy Everett Collection/Gotham/FilmMagic
He recalled calling Ryans agent and was like, Is this happening?
He told me Ryan was totally supportive because Ryan loves Kal.
We paid him $10,000, and he was a beautiful man of his word.

Kal Penn and John Cho inHarold & Kumar Go to White Castle(2004). (New Line/Courtesy Everett Collection)
Ryan joining that cast got the movie greenlit.
It was followed by the 2009 prequelVan Wilder: Freshman Year, starringJonathan BennettandKristin Cavallari.