Steak Sandwich with Herb Butter, Better Than Any Burger

This is my go-to steak sandwich recipe recipe, and it never lets me down.

Ask me to choose between a burger and a steak sandwich, and the sandwich wins every single time. There’s something about thin, juicy strips of steak against buttery bread and melted cheese that just feels like an upgrade — a burger’s fancier cousin who shows up looking effortless but clearly put in the work.

This has been a staple in my house for years, the kind of thing I pull together for a quick dinner or scale up when we’re hosting a crowd. It’s simple enough for a Tuesday and impressive enough that nobody will guess how little time it actually took.

Why You’ll Love This

It comes together in about thirty minutes, and the filling itself can be made well ahead of time and refrigerated or frozen, which makes it a genuine lifesaver on busy weeknights. The herb butter does a lot of quiet work here, soaking into the bread and tying the whole sandwich together, and broiling it open-faced means you get that bubbly, just-melted cheese in a couple of minutes flat.

Why This Works

Freezing the steak for a few minutes before slicing is the trick that makes paper-thin strips actually achievable at home — firm, cold meat holds its shape under the knife instead of squishing and tearing. And keeping the sandwich assembly separate from cooking, storing the filling on its own and building sandwiches right before eating, is what keeps the bread crisp instead of soggy and the cheese properly melty instead of rubbery from sitting too long.

How to Make a Steak Sandwich

Step 1: Make the Herb Butter

Combine the softened butter with crushed garlic and diced dill, mixing until evenly blended. Set it aside at room temperature so it stays spreadable.

Step 2: Slice the Steak

Slice the steak into thin strips. If you’re having trouble getting them thin and even, pop the steak in the freezer for a few minutes first — it firms up just enough to make slicing much easier.

Step 3: Sear the Steak

Preheat an oiled skillet over high heat. Add the steak strips and season generously with salt. Cook until just golden, then remove from the skillet and set aside — you don’t want to overcook it here, since it’ll get a little more heat later under the broiler.

Step 4: Caramelize the Onions

Slice the onion into half rings. Using the same skillet, sauté the onions until deeply golden brown, scraping up any flavorful bits left behind from the steak. Remove from heat and set aside.

Step 5: Assemble the Sandwich

Slice the baguette lengthwise and spread herb butter generously over both cut sides. Layer on the steak, followed by the caramelized onions, and top with slices of havarti cheese.

Step 6: Broil Until Bubbly

Keep the sandwich open-faced and broil for about 2 minutes, until the cheese is melted and bubbly. Watch it closely — broilers work fast and can go from perfect to burnt in under a minute.

Step 7: Serve Warm

Serve right away, while everything is still warm and the cheese is at its meltiest.

Tips for the Best Results

• Freeze the steak for a few minutes before slicing to get clean, thin, even strips.
• Don’t overcook the steak in the skillet — it gets a final touch of heat under the broiler.
• Make a big batch of the filling ahead and refrigerate or freeze it, assembling sandwiches fresh whenever you’re ready to eat.
• Watch the broiler closely; a couple of minutes is usually all it takes for the cheese to turn bubbly and golden.
• If you don’t have a broiler, a 450°F oven works too — just cook until the cheese is melted and bubbly.

Variations to Try

Ribeye is the most tender option, but top sirloin, skirt steak, or NY strip all work well too, especially if you’re feeding a crowd on a budget. Sautéed mushrooms and bell peppers are a natural addition to the onions. Swap the havarti for cheddar, Monterey Jack, or provolone depending on what you have, and a smear of blue cheese or a side of au jus for dipping both take this in a slightly different, equally delicious direction.

What to Serve With It

Crispy air fryer fries are the classic pairing and cut the richness nicely. A tangy pickled cabbage salad or a bright Caesar salad both work well on the side if you want something lighter to balance the sandwich.

Storage and Reheating

The steak and onion filling keeps in an airtight container in the fridge for up to 3 days, or in the freezer for 2 to 3 weeks. Thaw frozen filling in the fridge before reheating. Assemble sandwiches fresh and bake or broil until the cheese melts — this keeps the bread from turning soggy ahead of time.

FAQ

What’s the best cut of steak for this sandwich?

Ribeye is the most tender option, though top sirloin, skirt steak, and NY strip are all great, more budget-friendly alternatives.

Can I make the filling ahead of time?

Yes, refrigerate it for up to 3 days or freeze it for 2 to 3 weeks, then assemble and broil fresh sandwiches whenever you’re ready.

I don’t have a broiler — can I still make this?

Yes, preheat your oven to at least 450°F and bake until the cheese is melted and bubbly.

What can I use instead of onions?

Sautéed mushrooms or bell peppers both work well if you’d rather skip the onions, or simply omit them.

Can I marinate the steak first?

Yes, a marinade adds another layer of flavor if you have time — something like a carne asada-style marinade works especially well here.