Another positive sign for Kobe Bryant's marriage -- the NBA star took his estranged wife Vanessa out on a romantic lunch date today ... and they totally SPLIT A SANDWICH & SOUP COMBO MEAL!!!

The two rolled in to the PDM Bakery and Cafe in Newport Beach, CA this afternoon looking and acting very coupley -- despite the fact their divorce is still pending.

Sources tell us ... Kobe and Vanessa split the Tuscan chicken sandwich (served hot) and tortilla soup combo meal -- and washed it down with a pair of iced teas.

We're told the Bryants hung out at the restaurant for about an hour ... and couldn't have been nicer.

Vanessa filed for divorce back in December ... but it seems like they're all but reconciled these days. Not only did Vanessa support Kobe in London during the Olympics, she also attended the Lakers pre-season game last night.