Air Fryer Caramelized Onions
Description
Soft, sweet, deeply golden caramelized onions made in the air fryer using a two-stage butter method — covered to soften, uncovered to brown. Mostly hands-off, and far better than dry-roasted onion slices.
Ingredients
- 2 large sweet onions, about 1½ lbs, sliced ¼-inch thick
- 2 tablespoons unsalted butter, cut into small pieces
- 1 tablespoon olive oil
- ½ teaspoon kosher salt, plus more to taste
- 1 teaspoon balsamic vinegar, optional
- Pinch brown sugar, optional
Instructions
- Trim and peel the onions, halve them pole to pole, and slice into ¼-inch half-moons. Separate the layers with your fingers.
- Place the onions in a small foil pan or oven-safe dish that fits your air fryer basket. Add the olive oil and salt, scatter the butter pieces over the top, and toss to coat. Cover tightly with foil.
- Air fry at 300°F (150°C) for 20 minutes, stirring once at the halfway point. The onions will be soft and translucent but not browned yet.
- Remove the foil. Increase the temperature to 320°F (160°C) and cook for 15–20 minutes, stirring every 5 minutes, until deeply and evenly golden brown.
- Stir in the balsamic vinegar and a final pinch of salt. Taste and adjust. Serve warm.
Equipment
- Small foil pan or oven-safe dish
- Aluminum Foil
- Tongs
Notes
- Do not skip the covered stage — it's what produces caramelized rather than roasted onions.
- Cook in batches rather than piling the onions deeper than about 1½ inches.
- Never add water to a hot air fryer basket to deglaze.
- Store in an airtight container in the refrigerator up to 5 days, or freeze in ice cube trays up to 3 months.
Nutrition
Serving: 1ServingCalories: 135kcalCarbohydrates: 13gProtein: 1gFat: 9gSaturated Fat: 4gPolyunsaturated Fat: 1gMonounsaturated Fat: 4gTrans Fat: 0.2gCholesterol: 15mgSodium: 305mgPotassium: 200mgFiber: 1gSugar: 9gVitamin A: 177IUVitamin C: 8mgCalcium: 35mgIron: 0.5mg