Plant-Based Gluten-Free Sourdough Patty Melt

Cross Sectional of Two Gluten-Free Sourdough Patty Melts

Bring the diner to your home kitchen with this gluten-free and plant-based spin on the classic patty melt. A meatless burger patty situated between two slices of vegan cheese, caramelized onions, and a mesmerizing cashew sauce will satisfy your nostalgic cravings. Don't forget the side of french fries!


Recipe created by Katie Mathews // @farelyrooted


Gluten-Free, Vegan

Makes 2 Patty Melts

Prep Time: 45 minutes

Cook Time: 15 minutes



½  loaf (or 4 slices) Bread SRSLY Classic Gluten-Free Sourdough, cut into ½ in slices 

2 plant-based burger patties, homemade or store-bought (I used The Meatless Farm V/GF patties.)

1 batch caramelized onions (see below)

1 batch Cashew Burger Sauce (see below)

4 slices vegan cheese of choice (I used Miyoko’s Cheddar.)

1 TB Olive oil

Caramelized Onions

1 large yellow onion, thinly sliced

1 TB vegan butter (I used Miyoko’s brand.)

1 TB olive oil


Cashew Burger Sauce

1 cup raw cashews, soaked in water for 2 hours

½ cup water

2 tsp grainy mustard

1 TB tomato paste

1 shallot, minced

2 TB sweet relish

1 TB maple syrup

1 TB apple cider vinegar

1 tsp sea salt

1 tsp garlic powder



  1. To make caramelized onions, melt butter and olive oil in a cast iron skillet or non-stick pan on medium heat. Once melted, add sliced onions and stir to coat with butter + oil. Cook on medium heat for 5 minutes, stirring frequently to prevent burning, until onions have softened.
  2. Turn heat to low and cover the skillet or pan. Let the onions continue to cook at a low heat for 20-25 more minutes, stirring every 3-4 minutes and making sure they are caramelizing but not burning. If they start to burn, add a tablespoon of water, lower the heat, and stir more frequently. 
  3. The longer the onions cook, the more they will caramelize. They are done when they are lightly browned (or a caramel color) and very soft. Remove from heat and let cool. If you have leftovers, these will keep in the fridge for up to 5 days.
  4. To make cashew burger sauce, drain and rinse soaked cashews and add to a high-powered blender with the remaining sauce ingredients. Blend on high until very smooth, which might take several minutes.
  5. To assemble the patty melts, first make sure your patties are cooked through. If homemade, use cooked patties. If store-bought, cook according to package directions.
  6. Heat 1 TB olive oil in a cast iron skillet or grill pan on medium heat. Spread cashew burger sauce on 4 slices of bread. To two pieces of the bread, add one slice of cheese, followed by one burger patty, another slice of cheese, a spoonful of caramelized onions, and finally the other two slices of sourdough that you spread the sauce on. 
  7. Gently transfer sandwiches to the heated skillet or grill pan and gently press down on each melt with the back of a spatula to get the bottom piece of bread to sear in the pan. Cook the melts in the skillet for 4-5 minutes until the bottom slice of bread is golden and crispy, and then very gently flip the melts and do the same on the other side until the cheese is melted and both bread slices are golden and crispy.
  8. Serve immediately or keep the melts warm and “melty” in the oven at 350 until ready to serve. 
  9. Serve melts with extra cashew burger sauce for dipping. French fries are recommended :)