Your best option for meals is with a private chef without fail. However if you want to explore the Jaco Restaurant scene let your concierge know and they will assist on the best choices for your groups depending on what you want to eat and your budget. Most nice sit-down restaurants are fairly expensive but there are a ton of restaurant choices in Jaco including Steak, Chicken, Sushi, Thai, Seafood, Italian, among others. Our favorite high-end restaurant is Lemon Zest which is a little pricey but has a great menu and the service is excellent.
Costa Rican Restaurants (called Sodas) are best for lunch and usually are buffet style. There are a couple of good ones in Jaco and our favorite being Soda Garabito. You can eat for less than $10 per person including a drink too. A normal meal at a Soda is a protein (usually fish or chicken) with rice, beans, and a small pasta salad.
There are also a ton of casual restaurants as well serving hamburgers, sandwiches, fried chicken, to pizza so whatever you are in the mood for just let your concierge know and they will lead you in the right direction. There are not many USA fast food franchises in Jaco but there are a few including Pizza Hut, Subway and KFC.