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Close-up showcases the rich, golden-brown color and soft texture of caramelized onions, highlighting their melt-in-your-mouth quality for this flavorful recipe.
Lady Maria

Caramelized Onions: Melt-in-Your-Mouth Flavor Bomb

This caramelized onions recipe transforms simple ingredients into a flavor explosion. Cooked low and slow, the onions develop a deep, rich sweetness that enhances any dish, from burgers to soups to tarts. Patience is key to achieving that perfect melt-in-your-mouth texture and unforgettable flavor.
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Prep Time 10 minutes
Cook Time 1 hour
Total Time 1 hour 10 minutes
Course: Condiment, Side Dish
Cuisine: American, Versatile
Calories: 50
Ingredients Equipment Method Notes

Ingredients
  

  • 2 large yellow onions about 1.5 pounds
  • 2 tablespoons olive oil
  • 2 tablespoons butter
  • 1/2 teaspoon salt
  • 1/4 teaspoon black pepper
  • 1 tablespoon balsamic vinegar optional
  • 1 teaspoon brown sugar optional

Equipment

  • Large, heavy-bottomed skillet (cast iron recommended)
  • wooden spoon or spatula
  • Cutting board
  • Chef’s knife
  • Measuring spoons
  • Airtight container (for storage)
  • Parchment paper (for freezing, optional)
  • Baking sheet (for freezing, optional)

Method
 

  1. Peel the onions and cut them in half from root to stem. Thinly slice each half into half-moons, aiming for consistent thickness.
  2. In a large, heavy-bottomed skillet (cast iron is ideal), melt the olive oil and butter over medium-low heat. The fat should shimmer but not smoke.
  3. Add the sliced onions to the skillet, spreading them out in an even layer. Avoid overcrowding; cook in batches if necessary.
  4. Sprinkle the onions with salt and pepper. Stir to coat them evenly with the oil and butter.
  5. Reduce the heat to low. Cook the onions, stirring occasionally (every 10-15 minutes), for 45-60 minutes, or until they are a deep golden brown color and incredibly soft.
  6. Initially, the onions will release moisture. As the water evaporates, they will soften and turn translucent. Be patient as they brown and develop a sweet aroma.
  7. In the last 5-10 minutes of cooking, add the balsamic vinegar and brown sugar (if using). Stir well to combine and scrape up any browned bits from the bottom of the pan.
  8. The onions are done when they are a deep, rich brown color, very soft, and have a sweet and savory flavor. Taste and adjust seasoning if needed.
  9. Remove the caramelized onions from the heat and let them cool slightly before serving. They can be used immediately or stored for later.

Notes

For deeper flavor, try using a combination of yellow and red onions. Red wine vinegar or a splash of dry red wine can be substituted for balsamic vinegar. Store caramelized onions in an airtight container in the refrigerator for up to 5 days or freeze for up to 3 months. When freezing, spread them in a thin layer on a baking sheet lined with parchment paper, then transfer to a freezer bag once frozen to prevent clumping. Low and slow cooking is critical; rushing the process will result in bitter onions. If the onions start to burn, add a tablespoon of water and reduce the heat.