Hi! We have successfully created a garden without excessive use of water. We use the water from washing up the dishes and only top it up with fresh water occasionally. So long as there isn’t too much soap in the water it works fine. Also, we have created a compost bin - collected all food waste and prunings etc. This makes good compost. We have grown bananas and Swiss chard, but as we are not there all the time, we haven’t done much more in the way of fruit and veg.
As a gardener, you might be interested in this page about plants in Cape Verde -