Caramelized Onion Grilled Cheese (Printable)

Buttery sourdough with jammy caramelized onions and melted sharp white cheddar. Crispy outside, gooey inside comfort in 50 minutes.

# What You 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

# Steps:

01 - Heat olive oil in a large skillet over medium heat. Add 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 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 3-4 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 diagonally, and serve hot.

# Expert Tips:

01 -
  • The onions cook down into a jammy, almost sweet layer that tastes like you spent all day in the kitchen even though its just one pan.
  • Sharp cheddar cuts through the sweetness perfectly, giving you that salty, tangy bite in every gooey mouthful.
  • Its the kind of sandwich that makes you slow down and actually taste your food instead of inhaling it over the sink.
02 -
  • Do not rush the onions, if you crank the heat too high they will burn on the edges before they caramelize in the center.
  • Grate your own cheese instead of buying pre shredded, the anti caking agents in bagged cheese keep it from melting smoothly.
  • Let the sandwiches rest for a minute or two after cooking so the cheese sets slightly and doesn't all slide out when you bite in.
03 -
  • Use a heavy skillet like cast iron for even heat distribution and that perfect golden crust without hot spots.
  • Press the sandwich gently with your spatula while it cooks to help the cheese melt faster and the layers meld together.
  • If your onions start to stick or burn, add a splash of water to the pan and scrape up the browned bits, they add flavor.
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