Joe Montana is a badass ... first grabbing the alleged kidnapper who snatched his grandchild right inside his home, then grabbing some grub at a fancy restaurant.
Joe hit up Nobu in Malibu Saturday night, just hours after he and his wife, Jennifer, had an enormous scare. TMZ Sports broke the story ... and a 39-year-old woman got inside the Malibu home where Joe and Jennifer were staying, spotted their 9-month-old grandchild and scooped the infant up. She went to another part of the house, where Joe and Jennifer confronted her and got the baby back.