Ingredients

• 2 tablespoons olive oil
• 1 tablespoon butter
• 2 large red onions , thinly sliced
• 0.25 cups white sugar
• 1 cup dry red wine
• 0.25 cups balsamic vinegar
• salt to taste

Instructions

1. 1 Heat oil and butter in a large skillet over medium heat until butter melts. Add onions and sugar; cook and stir until onions start to caramelize, about 15 minutes.
2. 2 Pour red wine and balsamic vinegar into the skillet and bring to a boil. Reduce the heat to medium-low and simmer until liquid is evaporated, 15 to 20 minutes more. Season with salt.

Nutrition per serving