I'm impressed! Do you have a Culinary Degree or are you just a foodie?
To help keep your mirepoix fresh try and get your hands on “stor it” produce bags. These bags are designed to remove ethylene gas (released by aging/old produce) and let the produce “breath.”
They work great! I can julienne several bell peppers and just grab a handful as needed. Really keeps them fresh...for weeks!
You live in Ca right? I bought them at Dollar Tree for...ya, a dollar. Also FRiends, see the link.
These can be cleaned out and used over and over. Make sure you get all the air out each time though.
http://www.dollartree.com/Stor-It-Always-Fresh-Zipper-Seal-Reusable-Gallon-Produce-Bags-8-ct-Boxes/p314088/index.pro#BVRRWidgetID
I am a culinary school graduate It was civilian, traditional French battalion style, fine dining, Careme and/or Escoffier kind of thing where the final practical exam was making a perfect hollandaise directly over open flame (no double boilers) while the chef screamed at you.
And got honors from the Joint Navy/AF cook school when I went to that.
I've cooked all over the world, for a SecAF, and for 1500 of my closest and smelliest friends on deployment. And make a pretty good navarin for the fine dining side.
I'm more of a breakfast, sauce, soup and bread bitch than anything else, but I can cover grill or dishwashing if required.
/johnny