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Entrees/ Recipes/ Vegetarian Recipes

Mushroom-Cannellini Bean Patty Melts By Oh My

Vegetarian Patty Melts

Vegetarian Patty Melts

What do you get when you combine rye bread, a mushroom-packed veggie burger, slightly caramelized onions and swiss cheese? A fantastic meatless version of the classic patty melt sandwich that is hard not to love. Cooked up grilled cheese-style, this meal keeps finding its way to our dinner table time and time again.

While the recipe does take a bit of time, both the burgers and the onions can be made in advance and stored in separate containers in the refrigerator. When you are ready to eat, the sandwiches just need to be assembled and grilled up in a skillet, making for a quick and easy meal.

Vegetarian Patty Melts

Traditionally, patty melts are made with beef hamburger patties, along with rye bread, swiss cheese and caramelized onions. In our meatless version, plenty of baby bella mushrooms are used in the vegetarian patty, to help give the burgers a sort of meaty texture. Both fresh and dry herbs, tomato paste and worcestershire (make sure to look for a vegetarian variety) are also added to the burger base, to really increase the savory flavors. Cannellini beans, an egg, bread crumbs and flour are added to the mix, which help give the burger a nice and sturdy texture.

The mixture for the patties will be on the wet side, but you should be able to pat it into large burgers on the baking sheet. If it seems overly wet, you can add in extra flour, about 1 tablespoon at a time, until it reaches a point where you can form it into the patties. However you want to avoid adding too much extra flour, as this could dry them out after baking in the oven.

Vegetarian Patty Melts

Mushroom-Cannellini Bean Patty Melts

A meatless version of the classic patty melt sandwich. With a mushroom and cannellini bean veggie burger, caramelized onions and swiss cheese.
Prep Time: 25 minutes
Cook Time: 45 minutes
Total Time: 1 hour 10 minutes
Servings: 4 sandwiches


For the burgers:

  • 1 tablespoon olive oil
  • 16 ounces baby bella mushrooms stemmed and chopped
  • 1 15-ounce can cannellini beans, drained and rinsed
  • 1/4 cup minced onion
  • 2 cloves garlic minced
  • 2 tablespoons minced fresh parsley
  • 1/2 cup panko bread crumbs
  • 1/4 cup all-purpose flour
  • 1/2 teaspoon dried oregano
  • 1/4 teaspoon salt
  • 1/4 teaspoon pepper
  • 1 large egg
  • 1 teaspoon tomato paste
  • 1 teaspoon vegetarian worcestershire sauce

For the onions:

  • 1 tablespoon olive oil
  • 1 large onion thinly sliced
  • 1/4 teaspoon salt
  • Pinch of pepper

For assembling:

  • 8 slices rye bread
  • 4 slices swiss cheese
  • Softened butter


To make the burgers:

  • Preheat the oven to 350ยบF. Line a large baking sheet with parchment paper and set aside.
  • Add the olive oil to a large skillet set over medium heat. When hot, add in the mushrooms and cook until tender and the liquid released has been cooked off, about 8 to 10 minutes. Remove from the heat and set aside to cool slightly.
  • Meanwhile, add the beans to the bowl of a food processor. Pulse until about half of the beans are pureed, but the rest still have some texture. Add to a large bowl, along with the onion, garlic, parsley, bread crumbs, flour, oregano, salt and pepper. Add the mushrooms to the bowl of the food processor (save the skillet for later) and pulse until finely chopped. Add to the large bowl and mix to combine. Taste and season with additional salt and pepper if needed.
  • In a small bowl, beat together the egg, tomato paste and worcestershire with a fork. Stir into the bean / mushroom mixture. Pat the mixture into four large patties (about 4 inches in diameter) on the prepared baking sheet.
  • Bake for about 25 to 30 minutes, until firm and lightly browned.

To make the onions:

  • Meanwhile, carefully wipe out the large skillet you used for the mushrooms. Add the olive oil and set it back over medium heat. When hot, add in the onion, salt and pepper. Cook, stirring often, until lightly golden and slightly caramelized, about 15 minutes, turning down the heat to medium-low / low as needed so that they do not burn.

To make the sandwiches:

  • Heat a large griddle or a large nonstick skillet over medium heat.
  • Set four slices of the bread on a work surface. Top each with a burger patty, a slice of cheese, some of the onions and finally another piece of bread. Spread some of the butter on the top and bottom of each sandwich.
  • Transfer the assembled sandwiches to the heated griddle and cook, carefully flipping once halfway through, until golden brown on each side and the cheese is melted.
Craving more veg-friendly recipes? Shop our collection of vegetarian and vegan cookbooks!

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  • Reply
    July 29, 2015 at 10:22 am

    Those patties look fantastic! I’m always looking for new veggie sandwich ideas. It’s so easy to get burnt out on them (IMO). I’ll have to save this one and try it out ๐Ÿ™‚

    • Reply
      Ashley Jennings
      July 30, 2015 at 1:45 pm

      It’s always good to switch it up! Thanks Hannah!

  • Reply
    July 29, 2015 at 1:54 pm

    Wow! I have been trying to eat more meatless meals and this looks so so good! Thank you

  • Reply
    Jennifer @ Delicious Everyday
    July 29, 2015 at 9:59 pm

    Your veggie version of the patty melt sandwich looks absolutely delicious. I think even the meat lovers will adore this one. I can’t wait to try this!

    • Reply
      Ashley Jennings
      July 30, 2015 at 1:45 pm

      Thanks so much Jennifer – enjoy!

  • Reply
    Emma {Emma's Little Kitchen}
    July 30, 2015 at 12:29 pm

    YUM YUM! Looks like perfect veggie comfort food. Mushrooms and melty swiss cheese are always a perfect pair ๐Ÿ™‚

    • Reply
      Ashley Jennings
      July 30, 2015 at 1:44 pm

      Thanks Emma! Agreed – they go so well together!

  • Reply
    November 3, 2015 at 10:51 am

    If I wanted to make these vegan, do you think they’d hold up without the egg? Any recommendations on substitutions for the egg?

    • Reply
      Ashley Jennings
      November 5, 2015 at 7:38 am

      Hi Kristen – I’d probably use a flax egg in place of the regular egg just to help bind them together!

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