There is no scientific evidence to suggest that the primordial soup was a 'hearty pre-protein stew'. The concept of a primordial soup refers to a hypothetical, early stage in the evolution of life on Earth, where organic compounds accumulated in the oceans, providing a rich source of nutrients for the development of early proto-cells and life forms. It's important to note that the composition of the primordial soup is subject to scientific theories and ongoing research, and it is not described in terms of culinary dishes.