4: In a large saucepan over medium heat, melt 30 g butter then add the minced onion, salt and pepper. Cook for 1 or 2 minutes, stirring, without browning.
5: Pour in the potatoes and turnips, salt and pepper again and stir well for 2 or 3 minutes.
11: Brown to taste in a small frying pan with 30 g butter.
12: Divide the croutons and diced Saint-nectaire among your guests' bowls or plates.
13: Pour soup generously over the top, and enjoy.
Remarks
Blending the cooked vegetables is not essential, as it gives the recipe a more rustic feel. The stock cube isn't essential either - it's up to you. The recipe could of course be adapted with other vegetables or cheese, but it wouldn't be the same delicious Auvergne soup.