Take out a pot, heat up the olive oil and sauté the onions and sage in the oil
Peel the potatoes and chop them into chunks
Add the potatoes to the pot and stir
Now pour water to your pot
Remove the core of the apples (don't peel them) and cut the apples into rather thin slices
Add salt and apples to your soup and let the soup cook until the potatoes are done
Taste the soup and if necessary add some more sage to it
How strong the aroma of the sage will be depends on what time of the year you harvest the sage (especially when you use a fresh one from your garden), in summer the aroma is much stronger than in winter.