3. In a large bowl, toss frozen pierogi and onion wedges with half of the melted butter and a pinch of salt and pepper; arrange on the baking sheet with the cabbage. Add kielbasa to the baking sheet.
Add the kielbasa and cook over moderately high heat until lightly browned, about 4 minutes. Add the onion and cabbage and ... Season with salt and pepper, stir in the rice and serve.