Argonian's probably eat a lot of fish and other meat, roots and other food that grows wild. Bread and cultivated food probably less so. Do you have hearthfire? You can build a home in Hjaalmarch, the marshiest hold in Skyrim, or Lakeview Manor near Falkreath. Honeyside in Riften is in the Vanilla game, and might suit an Argonian well.
Only Rock Warbler Eggs, Blue Mountain Flowers and Butterfly Wings(regular ones) have restore health as their first effect. So if you want to use food for healing, these are your top choices. Blisterwort and Blue Dartwing have it as their second effect, so fairly easy to discover. If you build the Hjaalmarch house, you can have a fish hatchery which will cause the Dartwing to spawn.
Argonian bloodwine probably isn't Argonian in make. One of it's effects is underwater breathing, which they can already do. I'd drink the mildest thing you can find, unless the character is alcoholic. We don't have anything to suggest that Argonian's drink for fun. We know they drink Hist sap when they are young, and that's about it.