The new restaurant, to be called Slap Box Pizzicheria, will open in the span of two and a half to three months, after the two make some changes to the interior space.
The name comes from what Italian immigrants used to call pizzerias in the 1940s; slap box, also a nostalgic term, comes from a dated phrase that Thompson and Chang wants to revive.
"We want to recoin the phrase of 'slap box'," Thompson said. "American kids used to say 'grab a slap box' not 'grab a slice.'"
Slap Box's sauce recipe comes from an 85-year-old recipe from Brooklyn and takes 15-18 hours to make. The bread originates from San Francisco, where Thompson is originally from.
The menu will be the same as the one at 600 Degrees, with the addition of a few more specialty pizzas.
"You can't have a small menu unless you do something extremely crazy," Thompson said of the restaurant's limited, but quality offerings.