Ruth friday`s soup

4-5 turnips, cleaned and trimmed
4-5 sweet potatoes
1-2 big onions
water
salt and pepper
olive oil
fresh sage
a little butter

Sauté onions in olive oil. Add turnips and sweet potatoes, peeled and cut into chunks. Add salt and pepper to taste.
Cook in water till tender, then blend.
In a small frying pan, heat olive oil and a little butter, stir-fry fresh sage leaves till brownish. When serving soup, garnish with crumbled sage leaves.