Just came back from Costa Rica where we had and amazing food adventure, however, eating Organic (Organico) or Gluten Free (sins arina) is very tough to do.
One of our party is ciliac and needs to eat gluten free. And we all don't tolerate MSG which can be a big part of your meal if you are not careful. Most soups will use consomme' which has MSG and gluten in it and consomme is used sometimes in other parts of the cooking including cooking the vegetables. Some spice such as Bomba have MSG and gluten in them as well.
I found a gluten free section in Auto Mercado in Playas del Coco and we bought some cookies and while they had some pastas, you were really limited in buying things to cook at your hotel or condo. And organic products were severely limited so your best bet is to just eat fish out. It is amazing and if you grill the fish and are careful on what sauce is put on it, you will be in heaven!!
Gluten free eating out became easier as the fresh fish option and steamed vegetables and rice were usually a safe option. The chips and salsa generally were no problem for her as well just make sure the chips are maize (corn) and not flour (arina)
The key is to ask the waiter to make your meals without gluten or MSG and to season with only salt and pepper and butter. Most waiters will understand English although the concept of Gluten Free eating is not something they are familiar with.
Below is my bad attempt at Spanish to try and get your point across if there is a problem with communication.
sins gluten, arina, MSG, consomme = without gluten, wheat , MSG
sal y pimiento solamente = salt and pepper only
mantaquilla = butter
comida = food
hacer = to make
puede = can you
con = with
Puede hacer comida con sal y pimiento y mantaquilla sins gluten, arina, MSG and consomme'? Can you make food with salt, pepper and butter only and without gluten, wheat, MSG and consomme'?
They will look at your quizzically but will get the idea...and then you have to trust that they will make it accordingly. My friend did not have a problem once we specified her specific food prep requirements.
And also remember that most "foo foo drinks" that use vodka will use a gluten based vodka, not a potato vodka, so make sure you know what alcohol is going into your specialty drink.
Hope that helps!!