Instead of asking whether chickens or eggs came first, people should ask whether tomato soup or grilled cheese sandwiches came first.
I think it was the grilled cheese sandwich. And for centuries, people would go around, dipping their sandwiches in things, searching for the perfect combination.
Perhaps that was what Marco Polo did, seeking out the perfect dip for sandwiches.
Or Christopher Columbus. Or Sir Francis Drake.
On second thought, people going around with pots of soup, looking for things to dip in it makes more sense.
Thomas Edison claimed that he invented both, but Edison was a total dick.