I was reading about an attempt to reconstruct a recipe from Farmana, and I was wondering if there were any similarly old recipes/ similar attempts to reconstruct recipes.
There isn't a known date for this recipe, but it does allow me to elaborate on the second part of your question.
This comes from an interview with a Navajo chef sourced here. The chef describes taking a recipe which was common among East coast Native Americans (Clam and Sunchoke soup), and modifying it to suit modern palates. Instead of using just clams, sunchokes, and sea water, he adds leaks, onions, garlic, thyme, and bay leaf.
It's difficult to find a great source for this, but a similar recipe is claimed to be the inspiration for New England Clam Chowder. The Pequot Indians and other tribes in New England made a rich soup with clams (quahogs) and corn. Corn was eventually replaced with potatoes, and the clear broth was thickened with cream. Source here.