Prep Time: 15 minutes
Cook Time: 45 minutes
Total Time: 1 hour
- 6 lb. yellow onions*; peeled and sliced into half-rounds
- 1/4 cup vegetable oil
- 1/4 cup unsalted butter
- 1 Tbsp. Kosher salt
1. Heat oil over low heat in a large (6 quart) covered pot. Add butter and stir to melt.
2. Add onions and salt and stir to coat with oil and butter.
3. Cover and cook, stirring every 10 minutes to prevent burning, for 30 minutes. The onions will reduce significantly.
4. Remove cover and continue cooking, stirring frequently to prevent burning until they're mahogany brown - 20 to 30 minutes more.
5. Cool and then refrigerate or freeze. They'll keep in the fridge for 5 days and in the freezer for three or more months.
*Note: Yellow (Spanish) onions are milder and sweeter than white onions, but I've found super-sweet onions such as Vidalia or Walla Walla to be too sweet.