Ingredients
Caramelized Onions
2 tbsp butter
2 medium yellow onions, thinly sliced
1 tsp olive oil
1 tsp sugar (optional, helps caramelize)
1 tsp fresh thyme (or ½ tsp dried)
Salt, to taste
2 tbsp beef broth or white wine (optional, for deglazing)
Sandwich
4 slices thick bread (sourdough or country loaf)
1½–2 cups shredded Gruyère cheese
1 tbsp mayonnaise or softened butter (for spreading)
Instructions
Caramelize the Onions
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Heat butter and olive oil in a skillet over medium-low.
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Add onions, salt, and thyme. Cook slowly 15–20 minutes, stirring occasionally.
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If pan dries out, splash in broth or wine to deglaze and keep onions glossy.
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Onions should be deep golden and jammy.
Build the Sandwiches
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Spread mayo or butter on one side of each bread slice.
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Place two slices (spread side down) in a skillet over medium heat.
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Add a generous layer of Gruyère, then spoon caramelized onions on top.
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Add more cheese (this helps the “pull”), then top with bread.
Toast & Melt
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Cook 3–4 minutes per side, pressing gently, until bread is golden and cheese is fully melted.
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Lower heat if browning too fast.
Serve
Slice in half and enjoy while hot — expect that cheesy Gruyère stretch!
Great with:
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tomato soup
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simple green salad
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extra caramelized onions on the side
Notes
Adding a tiny splash of balsamic at the end of the onions adds depth.
Mix in a bit of mozzarella with Gruyère if you want EXTRA cheese pull.
Use a lid while melting to help the center get gooey.
- Prep Time: 10
- Cook Time: 25
Nutrition
- Calories: 650