Honeytrap is a little hidden gem within St Kevins Arcade off k'rd.
Although it's small it's jam packed with character and serves lots of great cabinet food (my favourite being the zucchini bread with herb butter). The menu items are also delicious.
So much of their food reminds me of an american diner. There's beef brisket sandwiches, no flat whites to be found (only bottomless filter coffee) and shakes.
I would recommend sitting upstairs. Yes there aren't many tables and you do need to watch your head but it's the perfect place to watch the world go by.
The prices are excellent as well.