Caramelized Onion and Gruyère Grilled Cheese Sandwich

By AislePrompt Editorial · ·

How this recipe was made — this recipe was drafted by AislePrompt's AI-assisted pipeline from technique templates and USDA-sourced nutrition data, and published by AislePrompt Editorial — see how AislePrompt recipes are drafted and published.

A comforting grilled cheese sandwich layered with sweet caramelized onions and nutty Gruyère melted between buttery toasted bread slices. This American-inspired sandwich and wrap recipe (vegetarian), ready in about 50 minutes, pairs unsalted butter, yellow onion, salt for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 520 calories and feeds 4, so it slots cleanly into a weekly meal plan and pairs well with a quick salad or grain on the side. Tap "Plan a meal with the AI" below to drop this recipe into your week and send the ingredients straight to Instacart. Nutrition values are approximate, calculated from USDA FoodData Central (fdc.nal.usda.gov) — verify against ingredient labels for any health-driven dietary plan.

Prep: 10 min Cook: 40 min Serves 4 American cuisine 520 cal/serving
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Ingredients

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Instructions

  1. Step 1: Melt 2 tbsp unsalted butter in a large skillet over medium-low heat. Add 2 thinly sliced medium yellow onions, 1 tsp salt, and 1/4 tsp black pepper. Cook slowly for 25-30 minutes, stirring frequently, until onions are deeply golden and caramelized.
  2. Step 2: Preheat another skillet or griddle over medium heat.
  3. Step 3: Butter one side of each of the 8 sourdough bread slices with the remaining 2 tbsp unsalted butter.
  4. Step 4: Place 4 bread slices butter-side down on the skillet. Layer each with 2 oz sliced Gruyère cheese and a generous portion of caramelized onions.
  5. Step 5: Top with the remaining bread slices, butter-side up, and cook for 3-4 minutes until the bread is golden and crispy.
  6. Step 6: Carefully flip sandwiches and cook for another 3-4 minutes until cheese is melted and the second side is toasted.
  7. Step 7: Remove from heat, let rest for 1 minute, then slice and serve warm.

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