Hi there, just a quick comment about the local meat vs. carrefour (or any supermarket for that matter). I have been going to a local butcher for the past two years and not once have I had a problem with the meat I've bought. Yes, on occasion there's a huge carcass hanging just outside, but those cuts are still covered in a layer of fat which is cut off when you buy it; that layer of fat essentially protects the meat from the pollution, flies, people, etc. Also, so you're aware, I've tried the meat from the supermarket, carrefour included, and have found it spotted or totally black/green the following day. That has never happened to my local meat, even if I keep it out for a day in a marinade...it's never, ever turned colors on me.
Give the local guy a try, you'll probably be happily surprised. The meat isn't any tougher and it has lots of flavor!!