what to eat after cardio

from what i have read , after doing weights you should eat protein , but what should you eat after cardio ?

I was always told to eat something like a jacket potato

I think a protein shake is good after a nice workout!

Same.

Here's the deal: you can get energy from burning carbs, or you can get energy from burning a combination of fat & protein.
Carbs produce quick bursty energy.
Fat/protein produces slow-burning, steady energy.
Your muscles need protein, and if you don't eat enough protein, your body harvests it from the muscles. But you want to lose fat, not muscle!
Before a workout, it's a good idea to eat/drink something with both carbs and protein, to make sure you have the energy you'll need to complete the workout.
After a workout, you should immediately drink/eat something with protein in it. This will 1. help repair any muscle damage quickly, and 2. keep the fat-burning metabolism going strong without losing muscle mass.