Look carefully for Mrs Mac's Kitchen when headed southbound out of Key Largo, it's easy to miss and not especially easy to turn around when you missed it!
As the previous reviewer suggested, Mrs Mac's is not at all a sushi place - indeed far from it. It's a diner, serving local seafood in standard formats.
The portions are hearty and the free refills of iced tea and lemonade are pleasant on a hot day. We weren't quite able to discover what makes Mrs Mac's as great as all the reviewers here say, though we did enjoy a lunch that included the fresh fish sandwich and we would recommend it if you're passing by.
