Caramelized Onion Grilled Cheese (Print-Friendly)

Buttery sourdough with jammy caramelized onions and sharp white cheddar. A golden, melty comfort sandwich in under an hour.

# 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

→ Extras

08 - Freshly ground black pepper, to taste

# Cooking 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 if desired to enhance sweetness and browning.
02 - Remove caramelized 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 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 from pan and let rest 2 minutes. Slice and serve hot.

# Expert Tips:

01 -
  • The onions cook down into something sweet and jammy that makes every bite feel indulgent without any fuss.
  • Sharp cheddar cuts through the sweetness with just enough tang to keep things balanced and interesting.
  • You get that crispy, buttery crust on sourdough that crackles when you press it in the pan.
  • It comes together with pantry basics but tastes like you put real thought into lunch.
02 -
  • Don't rush the onions or turn the heat up too high, or they'll burn before they caramelize and turn bitter.
  • Grate your own cheese instead of buying pre-shredded because it melts smoother and doesn't have that powdery coating.
  • Keep the heat medium-low when grilling the sandwich so the bread has time to crisp without scorching before the cheese melts.
03 -
  • Slice your onions as thin and even as possible so they cook at the same rate and caramelize uniformly.
  • Let the finished sandwich rest for a full two minutes before cutting so the cheese firms up just enough to stay inside instead of oozing out everywhere.
  • If you're making multiple sandwiches, keep the cooked ones warm in a low oven while you finish the rest so everyone eats at the same time.
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