Heat a rimmed stainless steel or nonstick pan (like the Always Pan) over medium heat (it should be large enough to easily accommodate your onions in a semi-even layer — the slices shouldn’t be piled high in the pan, or they’ll take longer to caramelize).
Add a little water to the pan — start with 3 Tbsp (as original recipe is written).
Add sliced onions and stir. Then cover.
Cook for a total of 30-40 minutes, opening the lid and stirring every 5 minutes. Be sure to cover again with lid after stirring — this helps them cook more evenly without the use of oil. Add 1 Tbsp (15 ml) water more at a time as needed to prevent sticking/ burning.
Once they start browning slightly, turn heat to low. How long you cook them depends on how deeply you want them caramelized. We found 30 minutes to produce a light golden brown color and sweet flavor, and 35-40 minutes to yield a deeper brown color and richer caramelized flavor. Be careful not to burn by keeping heat on low and adding more water only as needed to prevent sticking. NOTE: For reference, we added 1.5 Tbsp water and turned to medium/low at 9 minutes, added 1 more Tbsp water at 12 minutes (they were already golden brown), and turned heat to low. And we added 1/2 Tbsp more water and a pinch of sea salt at 21 minutes. Our onions cooked for a total of 35 minutes.
Near the end of cooking, add a pinch of salt and stir to enhance the sweet, caramelized flavor (optional). Stir, taste, and add more to taste as needed.
Use immediately on salads, sandwiches, wraps, bowls, and more! We include a few ideas above. Store leftovers covered in the refrigerator up to 3-4 days (though best when fresh). If storing for later, freeze into ice cube molds. Once frozen, transfer to a freezer-safe container and store for up to 1 month (sometimes longer).
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Notes
*We tested this recipe in a stainless steel skillet and the non-stick Always Pan (see our Always Pan review here). Both worked well, but we slightly preferred how the Always Pan was easy to work with, yielded perfectly browned onions, and naturally prevented sticking. *Nutrition information is a rough estimate calculated without optional ingredients.