Is smoked kielbasa already cooked?
Often, yes, but not always. Check the label. Many packages say “fully cooked” or “smoked,” which means you are mostly browning and heating through. If your package says “fresh” or “uncooked,” cook it to 160°F (71°C) for pork or beef, or 165°F (74°C) if it is poultry-based.
Do I have to slice it?
Nope. You can cook it in whole links, but slicing gives you more surface area, which means more browning, which means more happiness. If cooking whole, score lightly so it does not burst.
What is the best pan for kielbasa?
Cast iron is great for browning, but any heavy skillet works. Nonstick will brown less intensely, but it is still tasty.
What mustard should I use?
Dijon gives a smooth tang, spicy brown adds texture, and whole grain looks fancy without trying. Yellow mustard works in a pinch, but consider adding a touch more honey.
How do I keep the onions from burning?
Turn the heat down after the sausage browns. If the pan looks dry, add a small splash of water or broth and scrape up the browned bits. That is flavor, not danger.
What should I serve with it?
Mashed potatoes, buttered noodles, sauerkraut, roasted cabbage, rice, or crusty bread. Also a simple cucumber salad if you want something crisp and cool on the side.