Melt ½ stick of butter in crockpot (sprayed w/ lots of Pam). Add 1# Kielbasa cut into 2” pcs. Top with 2 bags frozen Pierogies (your choice of flavor). In large saucepan melt ½ stick butter add 1 large thinly sliced onion & six slices chopped bacon. Sauté until onions are golden and bacon is starting to brown. Add 1 pint of heavy cream and 1 Tbs Balsamic vinegar. Reduce heat and simmer 3-4 minutes stirring constantly. Top Pierogies with 4oz shredded cheese. Add 1 – 8oz ctn sour cream to onion mixture and stir until smooth. Pour over the Pierogies. Cook on high for 2 hrs and stir to blend. Cook on low 2-4 hours. After stirring add salt, pepper, & Thyme to taste.