Onion Recipe

Prepare onions

Peel the red and white Spanish onions. Slice each onion thinly into half-moons about 3-4 mm thick. Combine the sliced red and white onions in a bowl so you have approximately 4 cups total (about 2 cups red, 2 cups white).

Start cooking onions

Heat a large wide skillet or sauté pan over medium heat. Add the olive oil and butter and let the butter melt and foam lightly but not burn.

Add the sliced onions to the pan, spreading them in an even layer. Sprinkle the sugar over the onions (this encourages caramelization). Stir to coat, then reduce heat to medium-low. Cook the onions gently, stirring every 3–5 minutes so the outer edges brown but do not burn. This slow cooking will take about 25–35 minutes until onions turn a deep golden-brown and very soft.

When the onions are about two-thirds caramelized (soft and beginning to color), add the minced garlic and continue to cook, stirring, for 1–2 minutes until fragrant. Keep the heat low enough that the garlic does not burn.

Deglaze and simmer

When the onions are richly browned, increase heat to medium and pour in the white wine (if using) to deglaze the pan, scraping up any browned bits with a wooden spoon. Let the wine reduce for 1–2 minutes.

Add the vegetarian stock (about 1 cup). Stir, bring to a gentle simmer, then reduce heat to low. Simmer uncovered for 5–8 minutes so the onions absorb flavor and the liquid reduces slightly, creating a glossy, saucy consistency. If the mixture becomes too dry before the onions are tender, add the optional extra stock 1–2 tablespoons at a time.

Taste the onions and season with salt and freshly ground black pepper. If using thyme, stir in the leaves now and simmer 1 minute to release aroma.

If you want a touch of acidity and deeper color, stir in the balsamic vinegar at the end and cook for 30 seconds. Adjust seasoning to taste.

Remove from heat. Let the caramelized onions sit for 5 minutes to thicken slightly. Serve warm as a condiment, topping for toast, pizza, tarts, or stirred into soups and sauces. Refrigerate leftovers in an airtight container for up to 4–5 days or freeze up to 3 months.