One of the first things we would need to do to eliminate hunger is stop depriving nations of much needed vital supplies enabling them to thrive as a society. The likes of Nestle would not trying to buy water as a commodity to hold us to random.
However, on a more practical level, I believe we all need to much more aware of food waste, and grow in what suits out environment.
If every garden/roof/ community area had a growing area we could all share the food in the community grows if you wanted. That is easily said in Wales and the UK where it is easy to grow food with a good weather temperament and nutrient rich soil.
In countries like Africa where water is scarce and the sun is dangerously hot, not only could you put out a lot of solar panels but you could build large polytunnels for the plants which would cause condensation to form, maybe if there were enough plants you could collect the water and recycle it in many ways.
In countries with a long winter season and a lack of sunlight not only could store a lot of food, but by storing energy in the summer months could power some sunlight lamps to enable food to grow.
Saving seed would be essential so that we would never run out and would be practised at every season.
As we know certain foods grow better in a certain environment as with seasons being varied across the world utilising the best growing times for each country is essential to ensure that enough food would be produced in the best environment.
This would also meant that every country contributed throughout the year in one way or another.
Food storage could be achieved by underground containers of sorts that kept food cool and safe. A lot like a pantry in the house, however by placing underground no electric would be needed.
I do believe we can feed the world, but I believe the world would have to be less picky about what it wants to eat!