The spiders are part of the restaurant's mission to champion Khmer food from the present and dating back to the Khmer Kingdom of over 1,000 years ago while also helping provide work and a new life for street kids.
Cambodia's traditional specialties are less well-known than Western-friendly pad thais and rice-paper rolls from bigger neighbours Thailand and Vietnam although many regional dishes have their roots in Khmer cooking.
But with Cambodia rapidly developing, restaurants such as Romdeng are helping spearhead a comeback, said founder Sebastien Marot and top chef Sok Chhong who put together the cookbook "From Spiders to Water Lilies."
While the spiders may seem like a gimmick, the restaurant also has a serious social mission – getting young people off the streets and into employment and education.
Run by Cambodian non-profit Mit Samlanh or Friends, Romdeng and its sister restaurant Friends are staffed by former street kids who design the menus, cook the dishes, wait tables, and even sew the silk cushions for the chairs.
So what will Cambodia's breakthrough dish be if tarantulas are not to everyone's taste?
The country is considering submitting its "prahok" fish paste and peppercorns from the southeastern town of Kampot for trademarking as distinctive national products but it is "amok" curry that probably has the widest crossover appeal.
Milder than other curries, as Cambodia's traditional dishes were first cooked up in the days before traders introduced chilli to the region, it is named after the dark green amok leaf that's shredded into the dish as a seasoning.
True converts to Khmer cooking can end the meal with a commitment by buying the cookbook that feeds its profits back into the endeavour.
For more information on this project go to www.streetfriends.org.