Jeff Bezos, Lauren Sanchez Dine at Strip Mall Chinese Restaurant

Jeff Bezos and Lauren Sanchez might be worth billions -- but they're just like us ... 'cause sometimes, they just want some basic lo mein, and when they do -- they dine in.

The Amazon founder and his fiancée -- who are quite accustomed to the high life -- rolled into a relatively dinky restaurant in Miami Sunday called Tropical Chinese and they sat down for a meal with another couple for dinner.

If you think they'd stand out like a sore thumb in a joint like this ... well, you're right. As you can see in these photos obtained by TMZ -- Jeff and co. most certainly looked like celebs in a very normie part of town. And, in a modest establishment like this -- perhaps doubly so.

The reason we know that's true ... some of the restaurant patrons -- and some staff too, it seems -- came over to chat it up with JB and his crew ... apparently in awe he was there.

Jeff didn't seem to mind the attention ... he was seen smiling and yukking it up with the commoners -- and once he and his party were finally able to sit down and munch, we're told they appeared to be delving into the Peking duck ... which goes for about $78 there.

It's a whole two-course deal there and certainly one of their pricier offerings. Everything else is fairly affordable ... a fried rice order at this place costs between $15 and $26.

Considering Jeff and Lauren are used to a certain standard of living in their day-to-day -- this must've been a nice change of pace for them. Hey, billionaires need greasy noodles too!