How to Caramelize Onions

Caramelizing onions is not hard, but it does take a little patience, since you want to cook the onions slowly enough that they brown without burning. Put some music on, or a great audiobook or podcast, to keep you company while you cook. Use caramelized onions on burgers or sliders on a sandwich or pizza, or in an omelet. 

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Hands-on time: 30   |    Total time: 30   |    Makes: 1 Cup


Sharp knife (adult needed)
Cutting board
Medium-sized skillet
Measuring spoons
Heatproof spatula 


2 tablespoon olive oil
2 large red onions
1⁄2 teaspoon salt
1 teaspoon fresh rosemary leaves or 1⁄2 teaspoon crushed dried rosemary
Water, about 4 tablespoons


Wash your hands with soap and water, then gather all your equipment and ingredients and put them on a counter.

  1. Chop the onions: Trim the root and stem end off the onion, then cut it in half from end to end. Peel off the papery skin. Put the flat side down on the cutting board, and cut the onion into slices one way and then into slices the other way, so that you end up with a grid of little squares.
  2. Put the skillet on the stove, add the oil, and turn the heat to medium. Add the onions, salt, and rosemary, and cook for 10 minutes, stirring occasionally.
  3. Turn the heat down to low and cook until the onions are lightly browned and almost syrupy, about 35 to 40 minutes, stirring occasionally at first and then frequently as they start to brown. If the pan starts to seem too dry, add water, 1 tablespoon at a time. (You might be surprised by how much the onions shrink!)
  4. Use right away, or cover and refrigerate up to 2 days.