Caramelized Onion Grilled Cheese (Printable)

Buttery bread with sweet caramelized onions and sharp cheddar cheese melted to perfection for an elevated comfort sandwich.

# 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, optional

→ Seasonings

08 - Freshly ground black pepper to taste

# How To Make It:

01 - Heat olive oil in a large skillet over medium heat. Add the sliced onions and salt, stirring to coat. Cook, stirring occasionally, for 20-25 minutes until deeply golden and caramelized. Add sugar halfway through if desired to boost 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 pile 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 3-4 minutes per side, pressing gently, until bread is crisp and golden and cheese is melted. Adjust heat as needed to prevent burning.
05 - Remove from pan, let rest 2 minutes, slice, and serve hot.

# Expert Suggestions:

01 -
  • The onions cook down into something almost sweet and deeply savory, transforming a simple grilled cheese into something you'd order at a cafe.
  • It uses pantry staples and comes together in under an hour, but tastes like you put in way more effort.
  • The contrast between the crisp, buttery bread and the soft, melty interior is pure comfort in every bite.
02 -
  • Don't rush the onions—if you crank the heat too high, they'll brown on the outside but stay crunchy inside instead of turning soft and sweet.
  • Use medium-low heat when grilling the sandwiches so the cheese has time to melt before the bread burns, and resist the urge to flip too early or the bread won't get that perfect crisp.
03 -
  • Grate your own cheese instead of buying pre-shredded—it melts smoother and faster without any added anti-caking agents getting in the way.
  • Let the finished sandwiches rest for a minute or two before slicing so the cheese firms up just enough to hold together and you don't lose half the filling on the first bite.
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