I made potatoes au gratin with kielbasa a couple of days ago which I’ll definitely make again:
4 Klondike Rose potatoes sliced ¼” thick
1 onion, sliced into half moons
4 large garlic cloves smashed and minced
3 springs fresh rosemary
Boil in salted water until potatoes are done and onion is translucent. Drain and remove rosemary stems.
You will also need:
1/3# sliced, fried kielbasa
2/3 C shredded cheddar cheese, divided
Layer half of potato/onion mixture in bottom of casserole.
Add a layer of shredded cheddar cheese.
Add a layer of kielbasa, sliced thin and fried lightly, about 1/3#
Add last half of potato/onion mixture
Top with another layer of shredded cheddar.
Cover with foil and bake at 350° for 20 minutes, uncover and bake another 10 minutes.
Using red potatoes helps because they hold their shape when boiled.