How would you heat these sausages?

[Medicaltextbook]

I bought some Polish sausage (see photo) best Silesian sausage. Can be eaten hot or cold, but there are no cooking instructions. How would you heat them? In the oven? Boil?
Thanks

My first thought was poach/simmer them. Then I googled how to cook kielbasa and got further suggestions to roast, grill or fry (sliced or whole).

But maybe someone with more knowledge of them will be along soon to offer more expert advice.

Quick bump before I start cooking

Just like bratwurst, fry, grill, bbq

Did them in the oven and it was fine, a lot less cleaning up afterwards than frying.