Caramelized Onion Grilled Cheese (Printable)

Buttery bread filled with sweet caramelized onions and sharp white cheddar. A simple yet elegant comfort sandwich perfect for lunch.

# Ingredient List:

→ 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, optional

→ Extras

08 - Freshly ground black pepper to taste

# How To Make:

01 - Heat olive oil in a large skillet over medium heat. Add sliced onions and salt, stirring to coat evenly. Cook, stirring occasionally, for 20-25 minutes until deeply golden and caramelized. Add sugar halfway through if desired to enhance sweetness and browning.
02 - Remove onions from heat and set aside. Wipe out skillet if needed for cooking sandwiches.
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 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 3-4 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, let rest 2 minutes, slice diagonally, and serve hot.

# Expert Hints:

01 -
  • The onions cook down into a jammy, caramelized layer that tastes like you spent all day in the kitchen, even though it's just one skillet and some patience.
  • Sharp white cheddar melts into every crevice, balancing the sweetness of the onions with a tangy bite that makes each mouthful feel complete.
  • It's the kind of sandwich that works for a quick lunch or a quiet dinner when you want something that feels like a hug.
02 -
  • Don't rush the onions on high heat or they'll burn on the edges before they soften in the center, patience here is what turns them sweet and jammy.
  • Butter the bread all the way to the edges, not just the middle, or you'll end up with pale, soft corners that don't crisp up in the pan.
  • Use medium-low heat when grilling the sandwich so the cheese has time to melt before the bread burns, and press gently with the spatula to help everything meld together.
03 -
  • 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.
  • If you're making more than two sandwiches, keep the finished ones warm in a low oven while you cook the rest so everyone eats at the same time.
  • Let the sandwich rest for a minute or two after you pull it from the pan, it gives the cheese a chance to set slightly so it doesn't all run out when you slice it.
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