Mini Crustless Caramelized Onion & Cheese Quiches

1. Heat oil in a large pot over medium heat. Add onions and 1 teaspoon salt; stir to coat. Reduce heat to low and cook, covered, for 5 minutes. Remove the lid and stir. Cook, uncovered and stirring every few minutes, until the onions are melted and a deep amber brown, 35 to 45 minutes. If fond (brown coating) builds up on the pan, add water, 1 tablespoon at a time, to deglaze the pan, then use a wooden spoon or spatula to scrape all that flavor back into your onions. Transfer the caramelized onions to a large bowl and let cool to room temperature, about 20 minutes.

2. Preheat oven to 375°F. Coat two 24-cup nonstick mini muffin tins with cooking spray.

3. Whisk eggs, half-and-half, pepper and the remaining pinch of salt in a large bowl. Combine the onions, cheese, nuts (if using) and thyme (or parsley) in a medium bowl; mix well. Add the onion mixture to the egg mixture; whisk to combine. Working quickly, spoon the mixture into the prepared muffin cups, filling each about 3/4 full (about 1 1/2 tablespoons). Every so often, give the mixture a stir to ensure the ingredients are staying evenly suspended in the custard.

4. Bake, rotating the pans front to back and side to side halfway, until a knife inserted into the center comes out completely clean, 15 to 20 minutes. Immediately invert the muffin tins to transfer the mini quiches onto a baking sheet. Let cool on the sheet pan to room temperature, about 15 minutes.

To make ahead

Refrigerate caramelized onions (Step 1) for up to 3 days or freeze for up to 3 months. Refrigerate quiches for up to 3 days. Or freeze uncovered in a single layer on a parchment-lined sheet pan until solid, then transfer to a freezer bag for up to 2 months.

Equipment

Two 24-cup nonstick mini muffin tins

Tip

For the best flavor, toast nuts before using in a recipe. To toast chopped nuts, place in a small dry skillet and cook over medium-low heat, stirring constantly, until fragrant, 2 to 4 minutes.