Thoroughly caramelizing onions, that is removing most of their moisture and converting the natural sugar to mahogany-dark, candy-like goodness, (not to mention the conversion of amino acids to brown deliciousness via the Maillard reactions), can be achieved on the cook-top or even in the oven. But doing so requires vigilance, careful heat control and a heck of a lot of stirring.
This method requires a glass bowl and a microwave oven. So …
CARAMELIZED ONIONS, MICROWAVE-STYLE
- 4 large yellow onions (enough for 2 pounds, sliced thin)
- 1 tablespoon dark brown sugar*
- 1 tablespoon butter
- 1 teaspoon kosher salt
- 1/4 teaspoon baking soda**
- Peel onions and slice thin (3mm) on a mandolin, or quarter and run through slicing blade of a food processor. (I personally prefer the ceramic blade, hand-held mandolin by Kyocera and no, they don’t pay me to say that.)
- Place half the onions in a large glass mixing bowl and toss with half the salt. Add the rest of the onions and sprinkle with the remaining salt. (Although salt will certainly enhance the flavor of the final result, it’s being added here for it’s ability to pull moisture out of the onions.)
- Cover tightly with plastic wrap and microwave for 10 minutes.
- Uncover (carefully … steam hurts) and drain to pour off any excess moisture. Stir in the butter, baking soda and brown sugar.
- Microwave uncovered for 15 minutes.
- Stir thoroughly then drain excess liquid again.
- Microwave 15-20 minutes more at 3 minute intervals, stirring thoroughly after each until the desired level of brownness is achieved.
NOTE: All use of microwave is at high-power only.
* Although the onion will probably be sweet enough on their own, I like the complexity of the flavor that the molasses in the brown sugar adds.
** Adding even a small amount of baking soda increases the pH of the onions, which promotes browning. It’s the same reason pretzels are dipped in a lye solution before baking.
So now that you have caramelized onions …
1. Add them to a frittata
2. Top crostini with onions and goat cheese or something stronger like gorgonzola
3. Take finished onions and shredded Gruyere and toast until melted (photo below)
Recipe and images © Alton Brown, 2015.