Add the sliced onions and cook over medium-low heat, stirring occasionally, until softened and caramelized, about 15-20 minutes. Add the cooked pierogies and kielbasa back to the skillet with the ...

Cut the kielbasa into rounds 1/4-inch thick ... Chop into 1-inch pieces and add to the skillet along with salt. Cover and cook over low heat, stirring often and checking to make sure the leeks ...