1. Clean/wash the potatoes thoroughly, scrub with a veggie brush, if necessary. Cook in plenty of salted water. Depending on the size of the potatoes, this can take 20-30 minutes. When the potatoes are cooked, drain them and let cool down.

2. In the meantime, finely dice the bacon. Peel the onions and garlic – cut the onions into fine rings and finely dice the garlic. Finely grate the mountain cheese. Set aside.

3. Heat up a large frying pan with some olive oil and briefly fry the bacon until slightly browned. Add the onion rings and garlic and fry/cook for about 10-12 minutes over a medium-high heat. The onions should have softened and gained some color, but not look burnt. Remove from the heat and let cool down slightly.

4. Preheat the oven to 180°C (350°F) fan-forced. Lightly grease a 28cm tart tin*. Place the cooked potatoes in the tart tin and smash/mash them with a flat object to create a base. The potato layer should have the same thickness all around – bottom and sides. Brush the potatoes with some olive oil, sprinkle with a little salt and pepper, and bake in the preheated oven for about 14-15 minutes.

5. While the base for the onion tart is in the oven, prepare the filling. Mix the sour cream with eggs, sweet mustard, and caraway seeds in a large bowl. Season with nutmeg, salt, and pepper. Add the browned (and slightly cooled) onions and the grated cheese to the bowl and mix to combine. Set aside.

6. Take the pre-baked potato base out of the oven (be careful, it’s very hot!) and spread the onion mixture evenly inside the potato base. Place it back in the oven and bake for about 35-40 minutes or until the filling has set, and the top got some color. Take out of the oven and let cool down for some time. The onion tart tastes best when still warm.