Caramelized Onion Grilled Cheese (Printable Version)

Golden-brown bread layered with sweet, jammy caramelized onions and melted sharp white cheddar.

# 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

→ Seasonings

08 - Freshly ground black pepper to taste

# Step-by-Step Directions:

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 caramelized onions from heat and set aside. Wipe out skillet if needed. Butter one side of each bread slice. Place two slices buttered side down on a clean work surface.
03 - Top each buttered bread slice with half the grated cheddar cheese, then distribute caramelized onions evenly over the cheese. Sprinkle with black pepper. Cover with remaining bread slices with buttered side facing up.
04 - Heat skillet over medium-low heat. Place assembled sandwiches in skillet and cook 3-4 minutes per side, pressing gently, until bread is crisp and golden and cheese is completely 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 slow-cooked onions turn so sweet and jammy they taste like they belong in a fancy bistro, not your Tuesday night kitchen.
  • It uses ingredients you probably already have, but the result feels special enough to serve to someone you want to impress.
  • The contrast between crispy, buttery bread and gooey melted cheese with soft onions hits every texture you want in one bite.
  • It comes together faster than you think once the onions are done, and those are mostly hands-off time.
02 -
  • Don't rush the onions or crank up the heat, they need slow, gentle cooking to caramelize properly without burning or turning bitter.
  • Use medium-low heat when grilling the sandwich so the bread crisps up at the same pace the cheese melts, otherwise you'll end up with burnt bread and cold cheese.
  • Grate your own cheese instead of buying pre-shredded because the anti-caking agents in bagged cheese prevent it from melting smoothly.
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.
  • Use a cast iron skillet if you have one because it holds heat evenly and gives you the most consistent golden crust.
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