Boil the potatoes, strain, peel and cut into wedges.
Peel and chop the onion and fry it in a pan.
Cut the black pudding into cubes, add and continue to roast until the black pudding becomes loose.
Add the potatoes and fry for a while. Peel and press the garlic and add to the mixture.
Add salt and pepper to taste and serve the Blunzengröstl immediately.