Echo the above comments about crossing over West Street towards Tribeca.
I live in Battery Park City and there are a few restaurants here. However, the majority of them, while the food is good, are very expensive and are centered around delivery and take-out.
If you're visiting NYC and staying at the ES in BPC and want to eat great food in a nice restaurant and have a good dining experience, cross over West St.
If you just want a casual (and overpriced) dinner, walk south through the WFC and walk down South End Avenue where you'll find the aforementioned expensive casual dining spots including Zen (Upscale Chinese/Thai), Wave (Japanese), Cove (American), Picasso (NY Pizza).
If you do walk down to lower BPC, when you get to Albany St. & South End, look up and wave to my empty apartment!