Step 1

Preheat your grill to 300°F (150°C) to get it nice and hot, ready for cooking your kielbasa sausages.

Step 2

Slice 2 medium sweet onions into thin rounds and set them aside. Sweet onions have a milder flavor than regular yellow onions and are perfect for this recipe.

Step 3

Cut each of the 2 kielbasa sausages in half lengthwise, then score the sausages in a criss-cross pattern on both sides. This will help the sausage cook evenly and absorb more of the flavors.

Step 4

Heat a large skillet over medium heat and add 1 tablespoon of cooking oil. Once hot, add the sliced onions to the skillet. Cook the onions until they are translucent and soft, which should take about 5-7 minutes. Season with salt and pepper to taste.

Step 5

Place the scored kielbasa sausages on the preheated grill and cook until they are nicely charred, about 5-7 minutes on each side. Keep an eye on them to make sure they don’t burn.

Step 6

Once the sausages are cooked, add 1 cup of cheese to the skillet with the onions and stir until the cheese has melted and is evenly distributed.

Step 7

Toast 4 rolls in a toaster or on the grill for a couple of minutes until they are golden brown.

Step 8

Assemble the sandwich by placing a grilled kielbasa sausage on a toasted roll. Spoon the cheese-loaded onions on top of the sausage, and then spread mayonnaise on the top of the roll. Serve immediately and enjoy the delicious combination of juicy grilled sausage, melted cheese, and sweet caramelized onions.