Caramelized Onion Toast

Name: Caramelized Onion Toast
Prep time: 10 min
Cook time: 40 min
Total time: 50 min
Yield: 4 servings
Cuisine: American
Ingredients: 2 lb yellow onions, thinly sliced; 2 tbsp unsalted butter; 2 tbsp olive oil; 2 cloves garlic, minced; 1 tsp fresh thyme; 2 tsp balsamic vinegar; 8 slices sourdough bread, sliced; 1 cup Gruyere cheese, shredded; 1/2 tsp salt; 1/4 tsp black pepper

Deeply caramelized onions with garlic and thyme piled onto toasted sourdough and finished with melted cheese; the slow-cooked toast that took over Instagram Reels in July 2026.

50 minMediumServes 4480 cal/serving

AmericanAppetizerStovetop and OvenVegetarianLow CarbLow-SodiumPork-FreeCorn-Free

Ingredients

2 lb yellow onions, thinly sliced
2 tbsp unsalted butter
2 tbsp olive oil
2 cloves garlic, minced
1 tsp fresh thyme
2 tsp balsamic vinegar
8 slices sourdough bread, sliced
1 cup Gruyere cheese, shredded
1/2 tsp salt
1/4 tsp black pepper

Instructions

1

Heat the 2 tbsp unsalted butter and 2 tbsp olive oil in a large skillet over medium-low heat.
2

Add the 2 lb thinly sliced yellow onions and a pinch of 1/2 tsp salt. Cook, stirring occasionally, for 30 to 35 minutes until deeply golden brown and jammy, lowering the heat if they start to catch.
3

Stir in the 2 cloves minced garlic and 1 tsp fresh thyme and cook for 1 minute until fragrant.
4

Remove from the heat and stir in the 2 tsp balsamic vinegar. Season with 1/4 tsp black pepper to taste.
5

Preheat the broiler. Arrange the 8 slices sliced sourdough bread on a baking sheet and toast lightly under the broiler, about 1 minute per side.
6

Top each toast with the caramelized onions and a layer of 1 cup shredded Gruyere cheese.
7

Broil for 2 to 3 minutes until the cheese is melted and bubbling. Serve warm.

Questions

Can I make Caramelized Onion Toast dairy-free?

Yes. The dairy in this entry is 2 tbsp unsalted butter, 1 cup Gruyere cheese, shredded. Swap the butter for olive oil where it melts, or a plant-based block butter where it is creamed; the cheese for a plant-based melting cheese (expect a milder flavor). The richness shifts slightly, but the method does not change.

Can I make Caramelized Onion Toast gluten-free?

Yes. The gluten in this entry is 8 slices sourdough bread, sliced. Swap the bread or crumbs for a gluten-free loaf or gluten-free panko. Everything else proceeds as written.

How long does Caramelized Onion Toast keep?

Refrigerate leftovers within two hours and eat them within three days. Reheat covered in a 300 F oven until warmed through.

Can I halve or double Caramelized Onion Toast?

Yes. As written it serves 4. Every ingredient in this entry carries precomputed half and double quantities, and the app's batch dial rewrites them inside each step. Doubled, split it across two pans and rotate them halfway; one crowded pan bakes unevenly.

Serve it with

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