I am the biggest fan (maybe also consumer) of my mom’s strawberry pie. She usually bakes it, when the strawberries in our garden are mature. Therefore, the most important ingredients – the strawberries – are provided by “nature”. However, the seeds were bought anywhen in the past (so actually the supplier was a gardener or a buidling center). Furthermore, other ingredients (eggs, sugar, flour, salt, butter, jelly, whipped cream, lemon) need to be bought at the supermarket. The supermarket usually sources their products from the manufacturer (and if the manufacturer, who processes the raw materials, is not the raw material supplier at the same time, there is also a raw-material supplier).