In Lisbon:
Food:
We always like to do a food tour early in the trip to try a wide variety of food quickly and see what we want to eat more of. We went through Treasures of Lisboa Food Tour and they did great!
You CANNOT miss Jesus e Goes (which was featured on Somebody Feed Phil). The Holy Burger is absolutely worth it. I want another bite so badly!

Porto
We just went there for a day in Dec 2024 and we loved it. So many good food choices.

Madeira
Others have mentioned it, but Madeira is magical. Highly recommend.