Caramelized Onion Grilled Cheese (Printable Version)

Golden-brown sourdough sandwich with jammy caramelized onions, sharp white cheddar, and buttery perfection in every bite.

# What You'll Need:

→ Bread & Dairy

01 - 4 slices sourdough or country bread
02 - 2 tablespoons unsalted butter, softened
03 - 4 ounces sharp white cheddar cheese, grated

→ Onions

04 - 2 large yellow onions, thinly sliced
05 - 1 tablespoon olive oil
06 - 1/2 teaspoon salt
07 - 1/2 teaspoon sugar

→ Seasonings

08 - Freshly ground black pepper to taste

# Steps:

01 - Heat olive oil in a large skillet over medium heat. Add sliced onions and salt, stirring to coat evenly. Cook, stirring occasionally, for 20 to 25 minutes until deeply golden and caramelized. Add sugar halfway through to enhance sweetness and browning.
02 - Remove onions from heat and set aside. Wipe out skillet if needed.
03 - Butter one side of each bread slice. Place two slices buttered side down on a clean surface. Top each with half the grated cheddar, then distribute caramelized onions evenly over the cheese. Sprinkle with black pepper. Cover with remaining bread slices, buttered side up.
04 - Heat skillet over medium-low heat. Place sandwiches in skillet and cook 3 to 4 minutes per side, pressing gently, until bread is crisp and golden and cheese is melted. Adjust heat as needed to prevent burning.
05 - Remove sandwiches from pan and let rest 2 minutes. Slice diagonally and serve hot.

# Expert Advice:

01 -
  • The caramelized onions turn jammy and sweet, adding a layer of flavor that makes this feel like a restaurant sandwich.
  • It uses simple ingredients you probably already have, but the technique makes it taste special.
  • The balance of buttery, crispy bread and gooey melted cheese with soft onions is absolutely perfect.
  • It comes together in under an hour, most of which is just stirring onions while you catch up on a podcast.
02 -
  • Do not rush the onions, if you try to caramelize them over high heat they will burn on the edges and stay raw in the middle instead of turning sweet and jammy.
  • Use medium-low heat for grilling the sandwich so the cheese has time to melt before the bread gets too dark, I learned this after burning three sandwiches in a row.
  • Grate your own cheese instead of buying pre-shredded, the anti-caking agents in bagged cheese prevent it from melting smoothly and you will end up with a grainy texture.
03 -
  • Make a big batch of caramelized onions and store them in the fridge for up to a week, they reheat beautifully and you will find yourself making this sandwich all the time.
  • Press the sandwich gently with the spatula while it cooks to help the cheese melt into the onions and create better contact with the pan for even browning.
  • Let the sandwich rest for a couple of minutes before cutting, this keeps the cheese from spilling out all over the cutting board and makes for a much cleaner slice.
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