// Let's say this was in a seperate file, maybe a configuration like file

var layers = [
{
  "geoJsons": ['../food-rome.geojson', 'food-madrid.geojson', '../food-barcelona.geojson'],
  templateBuilder: buildMe
},
{
  "geoJsons": ['../food-rome.geojson', 'food-madrid.geojson', '../food-barcelona.geojson'],
  templateBuilder: aChiaPet
}]

// layers would come from said configuration file

for(var i=0; i < layers.length; i++) {
   var layer = L.mapbox.featureLayer().addTo(map)
   // ... iterate over geo json collection and build onto layer using template
    // ... set each set of geo json to new layer
}