Geesh! Just about every ethnic group around the world discovered - whether independently or through common ancestors (whether Noah or Lucy) - that slow cooking makes tough portions of an animal edible. Similarly, the discovery that herbs, spices and seasonings improve the flavor of foods. As for cooking over wood fire, what do DU-folk think humans used before electricity and natural gas came into use?!
For Lesson 2, the discovery that grinding, spicing/seasoning, and forming miscellaneous scraps of meat, offal, and fat into casings made from the offal maximizes the nutrition gained from each animal, preserves meat from spoiling, and can be very tasty. For Lesson 3, preserving meat through drying ...