Ingredients
1/4 cup Butter
1/4 cup Olive oil
2 1/2 pounds Vidalia Onions, or other sweet onions such as Walla Walla or Maui
2 tsp Sea salt
2 tbsp Thyme, dried
1 tsp Black pepper, freshly ground
1 cup Pure maple syrup
1/4 cup Balsamic vinegar
Preparation
1. Quarter and thinly slice onions (about 8 cups). In an extra-large skillet, heat butter and oil over medium-high heat until butter melts. Add onions and salt. Cook for about 5 minutes or until onions start to soften, stirring frequently. Reduce heat to medium-low; add thyme and pepper. Cover skillet; cook for 10 to 12 minutes or until onions are very tender, stirring twice.
2. Increase heat to medium-high. Add maple syrup; bring just to boiling. Reduce heat to medium. Cook, uncovered, for 15 to 20 minutes or until most of the liquid has evaporated, stirring frequently. Remove from heat; stir in vinegar.
3. Ladle hot mixture into hot, sterilized half-pint canning jars, leaving a ¼-inch headspace. Wipe jar rims; adjust lids.
4. Process filled jars in a boiling-water canner for 5 minutes (start timing when water returns to boiling). Remove jars from canner; cool on wire racks.