Place a large, deep skillet over medium-high heat then add the butter, vegetable oil, and liquid smoke. When the butter is melted, add the frozen pierogies in an even layer. Cook for 8 minutes, until browned, then turn the pierogies over and continue cooking for an additional 8 minutes, or until browned on the other side. Remove from the skillet and set aside, leaving the butter and oil in the pan.

Add the onion and cabbage to the skillet. Cover and cook for 3 minutes, stirring occasionally, until crisp-tender and lightly caramelized in places. Stir in white wine vinegar, salt, ground black pepper, and celery seed. Cook uncovered for 5 minutes, stirring frequently.

Adjust seasoning to taste then stir in the cooked pierogies. Sprinkle with chives and serve hot.