If you are vegetarian, omit the anchovies and use a hard cheese made with vegetable rennet.

But an estimated 90 percent of American cheese, for example, is made with cultured chymosin, a vegan rennet replacement made using genetically engineered Aspergillus fungi.

Cheese-making requires rennet, an enzyme that was once extracted from calf intestines but is now made by genetically modified bacteria or yeast.