Save The first time I made this sandwich, I was trying to use up leeks from my CSA box that had been sitting in the fridge too long. Something magical happened when they hit that butter and started turning golden and sweet. My kitchen smelled like a fancy bistro, and I realized I'd been underestimating leeks my entire life.
Last winter, my neighbor texted me at 7pm because she'd had a terrible day at work. I made two of these sandwiches and carried them over in their warm state. We ate them standing in her kitchen while she told me about her awful boss, and by the time we finished, neither of us remembered why we'd been stressed.
Ingredients
- 2 medium leeks: The white and light green parts become incredibly sweet when cooked slowly
- 1 tablespoon olive oil: Prevents the butter from burning during the long caramelization process
- 1 tablespoon unsalted butter: Adds richness that helps the leeks develop those deep, golden flavors
- Salt and black pepper: Just enough to season the leeks without overwhelming their natural sweetness
- 120 g Havarti cheese: This creamymelting cheese is mild enough to let the leeks shine
- 4 slices artisan or sourdough bread: A sturdy bread that holds up to all that melting goodness
- 2 tablespoons softened butter: For spreading on the bread to get that perfect golden crunch
Instructions
- Caramelize the leeks:
- Heat olive oil and butter in a skillet over medium heat, add sliced leeks with salt and pepper, and cook slowly for 12 to 15 minutes until they're soft and golden, stirring occasionally so they don't stick.
- Prep your bread:
- Spread softened butter on one side of each bread slice, getting it all the way to the edges for even browning.
- Build the sandwiches:
- Place two slices buttered side down, pile on those sweet leeks evenly, layer with Havarti slices, and top with remaining bread buttered side up.
- Grill to perfection:
- Cook in a clean skillet over mediumlow heat for 3 to 4 minutes per side until golden and crisp, pressing gently with your spatula to help everything meld together.
Save My daughter used to turn her nose up at anything with leeks, but now this is her request for birthday dinner every year. Watching her take that first bite, eyes widening as she realizes what she's been missing, that's my favorite part of making these.
Make It Your Own
Sometimes I'll add a thin layer of Dijon mustard on the inside of the bread before assembling, especially when I want something that cuts through all that richness. A little goes a long way and adds this sharp, tangy brightness that makes everything else taste more alive.
Sides That Work
A simple green salad with an acidic vinaigrette balances the heaviness perfectly. Or go full comfort mode and serve with tomato soup, but make it a good one. I like roasting canned tomatoes with garlic first for depth.
Timing Tips
You can caramelize the leeks up to two days ahead and keep them in the refrigerator. They actually develop more flavor overnight.
- Warm the cold leeks in the pan briefly before assembling your sandwiches
- Let the finished sandwich rest for a minute before slicing so the cheese sets slightly
- Use a sharp knife and saw gently to avoid pulling all the cheese out
Save Some days you need something simple, warm, and deeply satisfying. This sandwich has never let me down.
Kitchen Help
- → How do I caramelize leeks properly?
Heat olive oil and butter in a skillet over medium heat, then add thinly sliced leeks with salt and pepper. Stir occasionally for 12-15 minutes until they turn soft and golden brown. Lower heat if they brown too quickly.
- → Can I prepare the caramelized leeks ahead of time?
Yes, caramelize the leeks up to 2 days in advance. Store them in an airtight container in the refrigerator and reheat gently before assembling your sandwich.
- → What cheese alternatives work well?
Gruyère and Fontina are excellent substitutes for Havarti. Both have similar melting qualities and complementary flavors that pair beautifully with caramelized leeks.
- → How do I achieve perfectly melted cheese without burning the bread?
Use medium-low heat and cook 3-4 minutes per side. Gently press the sandwich with a spatula to ensure even contact with the skillet, promoting uniform melting and browning.
- → What are ideal serving suggestions?
Serve warm alongside a light green salad or creamy tomato soup. A crisp white wine like Sauvignon Blanc pairs beautifully with the rich, savory flavors.
- → Can I add other ingredients to customize this sandwich?
Absolutely. Try spreading a teaspoon of Dijon mustard inside the bread for extra depth, or add fresh herbs like thyme between the cheese and leeks.