Heat olive oil in a large skillet over medium heat. Add the diced onion and bacon, and cook for 2-3 minutes until the bacon starts to crisp up.
2 tbsp olive oil, 1 yellow onion, 4 bacon rashers
Stir in shredded potato. Cook for another 2-3 minutes until softened.
1 cup potatoes
Add the sauerkraut, gherkins, caraway seeds, salt, and pepper. Stir to combine and remove the skillet from the heat.
1 cup sauerkraut, 1/2 tsp caraway seeds, 1 tsp salt, 1/2 tsp ground black pepper, 1/4 cup pickled gherkins
Transfer the mixture to a greased casserole dish or add the grated mozzarella cheese straight to the top if the skillet is oven-proof.
1/2 cup mozzarella cheese
Bake in the preheated oven for 10-15 minutes or until bubbly and golden brown. Serve immediately.
Notes
Don't overcook the potatoes: If the potatoes are too soft, they will turn mushy.Adjust the seasoning: If you prefer a stronger flavor, add more caraway seeds or a pinch of red pepper flakes.Storage: You can typically store this sauerkraut casserole in the refrigerator for 3-4 days. To freeze this casserole, let it cool completely, then wrap it tightly and freeze for up to 3 months. To reheat, thaw overnight in the refrigerator and bake in a preheated oven until heated through.