Cast Iron Patty Melt Sandwich

This cast iron patty melt is the ultimate comfort food classic blending deeply caramelized onions bold sauce crusty bread and gooey cheese into each bite. It brings together the best of a grilled cheese and a juicy burger with an irresistible crispy edge only a cast iron skillet can deliver.

Patty melts became a cold weather tradition in my house because the first time I made them my family stood around the stove stealing cheesy corners straight from the skillet. Now we make them for cozy Friday nights in.

Ingredients

• Sweet onions: provide natural sweetness when slow cooked for a deep savory base. Choose onions that feel heavy for their size and have shiny tight skin.
• Unsalted butter: creates richness while allowing you to control the salt. Opt for good quality butter for best flavor.
• Mayonnaise: binds the sauce and adds tang. Look for whole egg mayonnaise for creaminess.
• Ketchup: brings a touch of sweetness to round out the sauce. Pick a brand with a short ingredient list.
• Yellow mustard: brightens the sauce’s flavor. Fresh mustard delivers a better zing.
• Garlic powder: incorporates more flavor into the sauce without fuss. Choose a powder that smells sharp.
• Ground black pepper: gives a little kick. Freshly ground is best.
• Angus sirloin steak burger patties: make these melts extra juicy. Use high quality burgers with visible marbling for better flavor.
• Thick cut sourdough or rye bread: stands up to the sauce and fillings. Select a fresh loaf with a chewy crust.
• Medium cheddar cheese: offers a mellow melt. Buy cheese in blocks and slice it for better texture.
• Swiss cheese: adds nutty creaminess. Look for pre-sliced from the deli for convenience.

Step-by-Step Instructions

Prepare the Onions:

In a large skillet melt a portion of the butter over medium-low heat. Add the thinly sliced onions and cook slowly for around thirty minutes stirring every few minutes. Keep the heat low so the onions turn soft deep gold and sweet with no burnt edges. This patient step builds a flavorful foundation for your melt.

Mix the Sauce:

While the onions cook stir together the mayonnaise ketchup mustard garlic powder and black pepper until smooth in a small bowl. Taste and tweak as needed. Set aside to let flavors meld.

Cook the Patty:

Heat a cast iron skillet over medium-high. Add butter and swirl to coat the surface. Place the burger patties in the hot skillet and cook according to your favorite doneness using package instructions or your own method. Set aside on a plate and wipe out the skillet for sandwich assembly.

Build the Sandwich:

Lay out all bread slices. Spread a generous layer of sauce on one side of each slice. Divide the caramelized onions onto half the slices then top each one with a cooked burger patty one cheddar and one swiss cheese slice and finish with another slice of sauced bread.

Pan Toast the Patty Melts:

In the skillet melt more butter over medium-low heat and swirl it to cover the base. Carefully add the assembled sandwiches. Cook until the bread is deeply golden and crispy on one side pressing gently with your spatula for that signature crust. Flip the sandwiches add the last bit of butter and move them around to soak up the melted butter. Cook until both sides are evenly toasty and the cheese inside is melted.

Serve Hot:

Cut each patty melt in half and serve immediately while the cheese is still gooey.

Save

Sweet onions have always been my favorite because their rich taste reminds me of Sunday lunches at my grandmother’s house where onions were always sizzling on the stove. Every time I smell them caramelizing I am instantly back in her kitchen.

Storage Tips

Store leftover patty melts tightly wrapped in foil or an airtight container in the refrigerator for up to two days. Reheat in a skillet over medium heat to preserve the crispy crust and melty cheese. Avoid microwaving if you can as it will make the bread soggy.

Ingredient Substitutions

If you cannot find steak burger patties use good quality ground beef shaped into thick patties and seasoned well. Provolone or Monterey Jack can swap for cheddar or swiss if needed. For a sharper sauce try adding a dash of Worcestershire or swapping yellow mustard for Dijon. If sourdough is unavailable rye bread makes a classic alternative and brings even more traditional flavor.

Serving Suggestions

Serve these patty melts with oven fries or a crisp green salad for contrast. Pickles and extra sauce on the side brighten every bite. For an old-fashioned diner feel add a mug of tomato soup or an old school chocolate milkshake.

Save

Cultural Context

Patty melts originated in American diners in the mid twentieth century blending burger culture with sandwich craft. Rye bread and caramelized onion have deep roots in deli cuisine which makes this dish feel both nostalgic and timeless for many home cooks.

Recipe FAQs

→ What type of bread works best for this patty melt?

Thick-cut sourdough or rye bread holds up well under the hearty fillings and provides excellent flavor and texture contrast.

→ How do you make onions perfectly caramelized?

Cook sliced onions slowly over low heat in butter, stirring occasionally, until they turn soft and deep golden brown, usually about 30 minutes.

→ Can I use a different cheese instead of cheddar and Swiss?

Yes, feel free to substitute with cheeses like provolone or American, which also melt smoothly and complement the flavors.

→ Should the patties be cooked before assembling the sandwich?

Yes, cook the beef patties in the cast iron skillet first to ensure they are thoroughly browned and cooked through before assembling.

→ What's the secret to crispy bread on the outside?

Generously butter the bread and cook the assembled sandwich over medium-low heat, pressing gently for even browning on each side.