Try my new budgeting app Cheddar 🧀
Better than YNAB, Mint (RIP), or EveryDollar.
5.0
(27)
Export 5 ingredients for grocery delivery
Heat olive oil and butter in a large skillet over medium heat; cook and stir onions and sugar in hot oil until onions start to caramelize, about 15 minutes. Stir red wine and balsamic vinegar into onion mixture and bring to a boil. Reduce heat to medium-low and simmer until liquid is evaporated, 15 to 20 minutes more. Season with salt.