Smashed burger patty melt featuring loads of caramelized onions, fresh microgreens, spicy mustard and a homemade horseradish aioli to tie it all together in this melt in your mouth crispy grilled sandwich.

Buckle up because you’re headed straight for flavour town! This is one hell of a sandwich. Crispy crunchy bread, thin beefy patty, loaded with buttery sweet caramelized onions and a sharp horseradish aioli to perfectly compliment it all. It’s pure joy and comfort food.

YOU MAY BE WONDERING..

What’s a patty melt? Well if you’re new around here, we’ve made one before. Check it out here. More commonly known in the U.S. across diner’s, but it’s basically a cross between a burger and a grilled cheese sandwich where you have a burger that’s served on sliced bread versus a bun.

MELT

The melt can either be cheese or caramelized onions or both. Cooking the onions until they are caramelized does that almost an hour to do. They can definitely be done ahead of time and reheated, but often we just start them right away and tend to other tasks in the kitchen while they cook. They are a MUST for this recipe. Too good not to make and honestly probably make the top 3 in our choice of ingredients we can’t do without for a burger.

HOW-TO

If you’ve got a griddle or flat top, we recommend making the sandwiches using that. Otherwise a cast iron skillet or the same pan use for your onions will get the job done just as good.

Once the sauce is made, the onions are cooked and the patties have been cooked, the first thing to do in assembling the melts is to butter the bread and place that side down onto the hot surface. fry that until it’s all crispy and toasted just as you would do if you were making a grilled cheese. Next thing is to sauce it up. What we’ve done is spread spicy mustard on the inside of one bread and the other we did a generous spread of our homemade horseradish aioli. Depending on the size of the bread you used, you may need to place two patties side by side on the piece of bread used to build your sandwich. Load it up with your greens as you would assemble your burger and fold the top “bun” in this case the other piece of bread overtop.

There’s no flip required here. We don’t want to mess up the sandwich and lose anything that’s inside. So we’re just toasting all the bread at the same time and when it’s all crispy and golden, placing it ontop and just giving it a quick hard press to seal shut your sandwich.

We hope you enjoy this recipe! If you give this recipe a try, let us know! Leave a comment, rate it (once you’ve tried it), and take a picture and tag it on Instagram! We love to see what you come up with. #thecommunalfeast Follow along our social media account on instagram for quick videos on how our recipes come together!

Print Recipe

patty melt

Smashed burger patty melt featuring loads of caramelized onions, fresh microgreens, spicy mustard and a homemade horseradish aioli to tie it all together in this melt in your mouth crispy grilled sandwich.

Prep Time15 minutes mins

Cook Time1 hour hr

Additional Time15 minutes mins

Total Time1 hour hr 30 minutes mins

Course: Burgers & Sandwiches

Servings: 4

Author: the communal feast

Ingredients

• 1 lb 80-20 ground beef brought to room temperature.
• 2 yellow onions peeled and thinly sliced
• 8 slices seeded sourdough bread
• salt and pepper
• mustard seed microgreens or arugula
• spicy mustard or dijon of choice
• 3 TBS butter
• Horseradish aioli
• 1/3 cup mayonnaise
• 2 garlic cloves minced
• 1 TBS lemon juice
• 2 TBS horseradish grated or substitute with store bought

Instructions

• Heat 2 TBS butter in a non-stick pan over medium-low. Once melted add the onions and cook stirring occasionally until golden brown and caramelized. About 45 mins.
• To make the aioli: combine all the ingredients together in a bowl. Stir until well combined. Let rest for 15 minutes.
• To shape the patties: allow the beef to come to room temperature. Form roughly the size of a 2 inch meatball using your hands to roll them out. It should yield between 8-10. Place between two sheets of parchment paper and use the back of a small side plate to press down each meatball into a smashed patty.
• Depending on the shape of the bread used, you may need to use 2 patties per sandwich, which is what is pictured here. If you’ve prepared more than needed, store each patty between parchment paper and freeze for the future. Use to make smashed burgers or repeat this recipe.
• Heat a griddle pan or use the same pan for the onions on medium heat. Cook the patties on both sides until browned and no longer pink. Season both sides with some salt and pepper. Top each patty with some caramelized onions during the last few seconds of cooking to reheat them.
• Wipe out the pan or griddle and return to medium heat. For this you can use tongs and scrape the fat with paper towel since it will be hot to the touch. Butter one side of each bread and place that side down to cook. We won’t be flipping the sandwich like you would a grilled cheese. So ensure that all the pieces of bread you will use to make a sandwich are toasting all at once.
• On the insides of the bread, spread some mustard on one side and the horseradish on the other bread. Next add the patties with the onions to the pieces spread with horseradish and build your sandwich on there. Finish with a handful of greens. Once the bread slices are perfectly golden, take the top pieces of bread (the one with the mustard) and sandwich that on top. Use a large spatula or back of a plate/pan to press that down and seal everything in place.
• Slice in half and serve immediately.