I have backpacked extensively for weeks at a time never using freeze dried food. A couple things that are great and easily available with Argentine ingredients:
Quinoa: As much protein than chicken, 1/3 cup dry makes a serving per person. A little olive oil, some knorr vegetable soup mix and pine nuts or walnuts. Saute the quinoa and nuts first, then add the soup mix and water to cover 2x, first then simmer. Better than freeze dried, just as light and way cheaper.
Pasta with salame: bring some pasta, cook, toss in some olive oil, red pepper flakes and parmesan, and some of your favorite salame. Maybe some sun dried tomatoes also for variety.
The other knorr packaged soups in the grocery store are also very good and light. Add some pasta in for a full meal, or make as a first course.
Lunch is cheese, crackers and, ugg.. more salame.
Hope this helps.