Kim Zolciak and Kroy Biermann are seemingly back on track once again after an explosive fight prompted one of their kids to call the cops ... this time, grabbing some lunch together with plenty of laughs.

The former reality TV stars went out Wednesday to a Japanese steakhouse and sushi joint, Kani House, in Duluth, Georgia ... sitting down for lunch in front of the hibachi grill.

Kim documented the date for social media -- as usual -- mentioning Kroy while filming and asking why he doesn't do knife tricks in the kitchen like the hibachi chef. Kroy laughs from off camera, joking that's what he does when Kim's not around ... which could actually make sense given the fact they're supposed to stay separated in the house.

The hibachi chef also created a rice heart for Kim and Kroy ... and she loves it, calling it "cute."

In the clips, Kim and Kroy are both laughing and seem to be having a good time ... a stark contrast from last week, when cops responded to their home for an explosive fight in front of their kids.

As we've told you ... Kim and Kroy were bickering over finances for weeks before things reached a boiling point, fighting after a seemingly nice public outing with their kids.

The estranged couple's in dire financial straits, but we've seen them go out for fancy dinners amid their money woes and nasty divorce ... and this seems to be a similar situation.