When you don’t eat processed foods on Pesach, you’ve got to make the most with what you’ve got. That’s where sauteed onions come in. I know some people who prepare vats of it and freeze it in individual portions. Most of my family’s meat and chicken Pesach recipes include sauteed onions as a base and some kind of braising liquid like wine or juice. The onions practically melt into the juice and the resulting sauce is delicious over mashed potatoes.