It’s essentially a pop up within an already existing bar ( Rocco’s)  that’s how he was able to open so quickly.

Pretty smart on Jax’s part which is shocking. Didn’t have to deal with licenses and permits, probably just a revenue share agreement.

added 3/11:

I went to Jax bar this weekend in LA and wow not what I was expecting at all. It seems like it’s a thrown together space but did not really look like a restaurant/bar at all. It had picnic tables in one area with very minimal decor and then another room with pictures of Jax from VPR but barely any seats. It was dead on a Friday night and by the time a waitress came to us with a menu we left because it was so bad. I would be shocked if this place lasts long honestly.