Build your next meal
Pair protein and carbohydrates with water. Try potatoes with eggs and vegetables, or rice with tofu and vegetables. Adjust the portion to your appetite and how demanding the session was.
When your next meal is a while away
A snack can tide you over. Try yoghurt, banana and oats, or a hummus sandwich with fruit. After a routine session, if your next meal is soon, eat it as planned.
When you train twice in one day
If two demanding sessions are close together, have an option with carbohydrates, protein and water ready after the first. If you have little appetite, start with a small snack you can comfortably eat and have a fuller meal later.
Sources

Hydratis, waterdrop or SiS: which hydration product should you choose?