In a large mixing bowl, mix green onion, red onion, lime juice, sardines, seasonings, eggs, bread crumbs and Dijon mustard.
Make sure ingredients are mixed well.
Heat oil in a medium skillet on medium high.
Make small, long croquettes from mixture.
Gently cook the sardine cakes in oil for 2 or 3 minutes per side.
Remove and place on a plate lined with paper towel. Let cool.