How long will leftovers last?

Store any leftovers in an airtight container in the refrigerator for up to 3 days. Reheat leftovers in the microwave or on the stovetop over low to medium heat.

Can I use whole milk instead of evaporated milk?

Evaporated milk has a thicker, creamier consistency than whole milk. In fact, it's similar in consistency to heavy cream, but with quite a bit less fat and fewer calories. So while you could swap in whole milk for the evaporated milk, I don't recommend it. Stick with evaporated milk for a richer, creamier cheese sauce.