If you are using kielbasa that is already smoked, you are mainly just getting heating the sausage through and getting a nice char on the exterior. Preheat the grill to medium-high heat (350 degrees Fahrenheit), placing the grill pan for the peppers on the grill grates while it heats up.
While the grill is heating, chop the bell peppers and toss them in olive oil, salt, and pepper.
Spray the grill grates with nonstick spray, or brush with a bit of oil. Then, add the peppers to the basket and place Polish sausage links on the hot grill.
Cook for 15 to 20 minutes with the lid on (for gas grill) or lid off (for charcoal grill). Occasionally stir the peppers around in the grill basket and flip the sausages, checking for doneness and ensuring they aren't getting too dark.
Near the end of the cook time, you can place the open buns on the grill to add some color, or you can toast them in a toaster, a pan, or in an air fryer.
Measure the sausages to ensure they have reached an internal temperature of 165 degrees Fahrenheit, then remove them from the grill to rest for a few minutes before serving. The bell pepper is ready when it's cooked through and lightly charred.
Serve sausages on a bun with the grilled peppers and toppings of choice.