The shooting went down Thursday afternoon outside Il Pastaio restaurant. We're told the shooter and 2 accomplices were after a $500,000 Richard Mille watch a man was wearing, and a woman was struck in the leg by gunfire.

An eyewitness told us the shooter fired off 3 or 4 rounds. The woman who was hit was having lunch near the man who was wearing the watch. The shooter made off with the timepiece -- and diners scrambled for safety -- as evidenced in the photos we obtained.

As far as we can tell no one else was shot, although diners were frantically checking themselves for bullet wounds.

Rapper DaniLeigh, who has been dating DaBaby, had just parked in front of the restaurant when the gunfire erupted.

As you can see ... the celeb hot spot is crawling with cops, and there's a ton of police tape wrapped around the restaurant's outdoor seating area, where a huge crowd of curious onlookers is gathering.

Celebrity photographer Tyler Shields was on the scene when gunfire erupted ... he said he herded a large group of people into a nearby parking garage when the shots rang out. Thankfully, he says everyone around him was OK ... and shared a message of love.

The Italian restaurant is extremely popular among famous folks ... we've seen lots of celebs dining there over the years, and it's where we get a bunch of them on camera.