Blanch the Nuremberg sausages in boiling water for about 3-5 minutes to heat through, then remove and pat dry with kitchen towels.
Heat the butter in a pan over medium-high heat. Add the sausages and fry until browned. Add the bay leaf, onion rings, beer, salt and pepper. Reduce heat to low and simmer for 15-20 minutes.
Remove from heat. Stir in the sour cream and chives. Taste and adjust seasoning with salt and pepper if needed.