Here's my 2 cents. You are staying on an island with 2 cultures so try a meal with real Dutch and Sint Martin French food.
For Dutch there are 2 choices, one upscale with a menu that has many non Dutch items. It's in a hotel, Holland House, and they can be hit or miss about taking non guests. The other one is pure Dutch with the menu in Dutch, but the nice couple will help you and there is a poster with some pics. You'll get to see some resident Dutch folks and hear the language while there. Don't let the low prices scare you off.
For French, there is only one place for me, Yvettes in Orleans. It's in a house and run by a long time resident family. Last time there I met 3 generations who were working there. We go for lunch and it is a rare time when we aren't the only tourists dining. Their hours are 12 to 2:30 and 6 to 10, closed Wednesdays. Very reasonable prices.

Here's a link to Mos, http://mosnackcorner.com/

You'll have a good time whatever you decide on. We have been going since the late 80's and still find new things to do.