Preheat the oven to 180°C. Place the whole potatoes in a large saucepan of salted water and bring to the boil. Simultaneously, boil the eggs in a separate pan for 9 minutes until hard set. Cook the potatoes until just tender but not falling apart, about 20 minutes. Drain both and allow them to cool slightly before peeling. Move on to slicing.

Slice the peeled potatoes into ½ cm rounds. Slice the hard boiled eggs evenly. Cut the kolbász into thin rounds to ensure even distribution of flavour. Uniform thickness ensures the layers bake evenly. Prepare the baking dish next.

In a bowl, stir the sour cream with a pinch of salt, black pepper and the sweet paprika. This seasoned cream will soak into the layers and bind them. Taste and adjust gently. Light seasoning is key as the sausage brings saltiness. Set aside for layering.

Grease a medium baking dish with lard or butter, coating the base and sides generously. Sprinkle the finely chopped onion evenly across the base. The onion softens beneath the layers and perfumes the dish subtly. Begin assembling the first layer.

Arrange one third of the sliced potatoes over the onion in an even layer. Season lightly with salt and pepper. Keep the layer compact without gaps. Add the next component.

Distribute half of the sliced eggs over the potatoes, followed by half of the kolbász. Spoon a third of the sour cream mixture over the top, spreading it gently to cover. This ensures moisture and richness. Continue building the next layer.

Add another layer of potatoes, season lightly, then the remaining eggs and sausage. Spoon over another third of the sour cream. Finish with the final layer of potatoes and spread the remaining sour cream evenly across the top. Smooth the surface neatly. Prepare for baking.

Bake uncovered for 35 to 40 minutes until the top is lightly golden and bubbling at the edges. The layers should settle and meld together. If deeper colour is desired, increase the heat slightly for the final 5 minutes. Remove and allow to rest.

Let the dish rest for at least 15 minutes before slicing. This helps the layers hold their shape. Serve warm with crisp pickled gherkins or a simple cucumber salad. A sprinkle of extra paprika before serving enhances both colour and aroma.