Also, it seems mayo is pretty standard, but I can’t see it on an Italian – only oil and vinegar for me. Your thoughts?
Personally, I think mayo provides a cool, creamy balance to the acidity and spiciness of the other ingredients. While you’re eating, it mixes with the oil and vinegar dressing to create a delicious sauce. Overall I think an Italian sub is better with it than without it, but it’s certainly not required.