1. Prepare the Onions: – Peel and cut off root and stem ends. – Slice evenly into thin half-rings for consistent cooking. 2. Heat the Pan & Add Fat: – Place a large skillet over medium heat. – Add oil, butter, or both — start with oil to stabilize butter. 3. Add Onions & Season: – Add onions to the pan and sprinkle with salt. – Stir to coat evenly in the fat. – Salt helps draw out moisture for faster browning. 4. Cook Low & Slow: – Once onions soften, reduce heat to medium-low. – Stir every 5–10 minutes to prevent burning. – Continue cooking for 45–60 minutes until deep golden-brown. 5. Deglaze (Optional): – If bits stick to the pan, add balsamic vinegar, wine, or stock. – Gently scrape to release flavorful browned bits. 6. Finish & Store: – Remove from heat when onions are soft and caramel-colored. – Store in an airtight container in the refrigerator for up to 4 days or freeze for up to 3 months.