Slice the onion into thin slices

Cut the kielbasa into 2" pieces, sliced diagonally if you're feeling fancy

Pour the oil into the skillet

Put the skillet onto the cooktop and preheat it over medium-high heat

Add the onion and kielbasa to the preheated skillet

Cook, stirring frequently, for 5 minutes

Be sure you're turning the kielbasa over to brown both sides and keep those onions from sticking to the pan

Add the vinegar, mustard, caraway, garlic powder, pepper, dill, and marjoram to the skillet

Stir everything until the ingredients are blended

Reduce the heat to low

Cook, stirring frequently, for five minutes