Spring onions look similar to green onions, but are a bit larger and stronger tasting. This recipe was developed by Melissa Clark and appeared in the New York Times. Romesco sauce is commonly served in the Catalan region of Spain. It can also be served as a sauce for meat, fish or vegetables other than spring onions. It can also be served on bread. This recipe takes 30 minutes using a microwave, 1 hour otherwise. I would probably decrease the oil in this recipe considerably, and add more warm water to make it less thick.