The Best Portobello Mushroom Sandwiches (with vegan version)

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If you're tying to find new ways to use up all those amazing garden fresh tomatoes, OR even if you have to go buy some tomatoes....These Easy + Cheesy Portobello Mushroom Sandwiches are a great recipe for you!

These sandwiches are so good they could easily be found on a great farm to table restaurant menu! BUT with this recipe you can make this restaurant style sandwich at home. Serve with simple mixed greens tossed in balsamic vinegar and olive oil, these melts are perfect for a light dinner or a fantastic main course for a casual lunch gathering.

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What you'll need to make these portobello mushroom sandwiches

4 Rolls Ciabatta

2 – 3 Portobello Mushroom Caps Sliced ¼ Inch Thick

1 Cup Whole Milk Mozzarella or Vegan Mozzarella (I use Miyoko's for vegan)

¾ Cup Parmesan Cheese (vegan or regular) Shredded

4 Fresh Roma Tomatoes

¾ Cup Panko Breadcrumbs

1 Cup Fresh Baby Spinach (or any greens you have)

1 Bunch Fresh Basil

2 Garlic Cloves Chopped or Grated

2 Large Eggs or ½ cup egg substitute if making vegan

¾ Cup All Purpose Flour

½ Cup Water, divided (¼ if making vegan, for tomato sauce only)

¾ Cup Olive Oil

1 ½ Tbsp Italian Seasoning

1 Tbsp Garlic Powder

1 Tbsp Dried Basil

3 Tsp Salt or to taste

2 Tsp Black Pepper or to taste

Balsamic Glaze – For Drizzling (Optional)

How to prep the portobello mushrooms

Preheat oven to 425°F.

Wipe the Portobello Mushroom Caps with a damp towel to remove any dirt. Slice the mushrooms into ¼ inch slices. (see photo below). Line a baking sheet with parchment paper or aluminum foil. Lay the mushroom slices out in an even layer.

Season the mushrooms with:

½ teaspoon of salt

¼ teaspoon of black pepper

Drizzle with 2 tablespoon of olive oil.

Bake mushrooms for 10 minutes (center rack)

While the mushrooms are baking, prepare the breading station for the mushrooms:

Grab 3 MEDIUM bowls.

In the first bowl combine and mix well:

¾ Cups (All Purpose) Flour

1 teaspoon Salt

1 tablespoon Basil

In the second bowl combine and mix well:

2 Large Eggs (½ cup egg substitute if making vegan)

¼ cup water (skip if making vegan)

1 teaspoon Salt

½ teaspoon Black Pepper

In the third bowl combine and mix well:

¾ cup Shredded Parmesan Cheese (regular or vegan parmesan. I like Violife for vegan)

¾ cup Panko Breadcrumbs

1½ tablespoon Italian Seasoning and 1 tablespoon Garlic Powder

Remove the mushrooms from the oven and cool.

Take each mushroom slice and dredge it in the flour, then egg mixture, then panko and parmesan mixture (be sure to coat both sides of each mushroom). Take the time to really press the panko and parmesan mixture on to each mushroom slices to ensure it sticks.

Lay each breaded mushroom slice on a sheet pan with parchment paper. Make sure to leave enough room between the mushrooms to allow the coating to get crisp in the oven.

Once all the mushrooms are coated, drizzle with olive oil and bake in the oven for 8 minutes. After 8 minutes flip each mushroom slice and cook another 5 minutes or until the crust is golden brown. Set to the side to cool.

How to make the tomato sauce:

Cook the tomato sauce while the mushrooms are cooking:

In a medium frying pan over medium-high heat combine:

¼ Olive Oil

Chopped tomatoes

1 teaspoon Salt

Cook for 10 minutes stirring and smashing the tomatoes gently with the back of a wooden spoon, occasionally. (You want the juices to release from the tomatoes and start to caramelize but not burn.)

After the tomatoes begin to get saucy golden, add:

2 Cloves Chopped Garlic

¼ Cup Water

Cook another 5 minutes, continue to stir occasionally. Taste and season with more salt and olive oil if needed. Set to the side.

How to assemble the Portobello mushroom Sandwiches:

Slice mozzarella into ⅛ inch slices (regular or vegan)

Slice your ciabatta rolls in half and lay 3-4 slices of the breaded mushrooms across the roll to see how many slices of mushroom fit nicely on each roll.

Remove the slices from the roll and lay in groups of 3-4 slices (depending on the size of your bread) on a sheet pan lined with foil or parchment paper.

Cover the mushroom slices with mozzarella and bake in the oven for 5 minutes. Then remove and set to the side.

Toast your rolls (open faced) for 2-3 minutes in the oven.

Once rolls are toasted, assemble the sandwiches:

Spoon 1-2 tablespoon of Tomato sauce on the bottom half of the roll. Add the mushroom and melted mozzarella on top of the sauce. Top it off with a few leaves of spinach and basil (or whatever greens you have). Drizzle with Balsamic Glaze, if desired. Add the top of the roll and presto!!!

Serve with a little love and enjoy! 

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How to Prep 1-2 Days in Ahead to Save Time

1-2 days before complete every step in the Prep The Portobello Mushrooms and the Prep The Tomato Sauce from the recipe below. Allow the mushrooms and sauce to cool and store in airtight containers until you are ready to use. Slice and store the mozzarella cheese in plastic wrap or an airtight container.

Reheating Before Service

All you have to do before service is reheat the mushrooms and tomato sauce (5 mins), melt the mushrooms with the cheese (5 mins) toast the rolls (2 mins) and assemble the sandwiches(3 mins). Reheating and assembling will take you all of 15 minutes. Your guests will be wondering how you ever pulled it off!

Reheating Process:

Mushrooms: Preheat oven to 400. Place breaded mushrooms on a parchment or foil lined sheet pan and cook 5 minutes or until heated through.

Tomato Sauce: Heat gently in a sauce pan over medium low heat for 5 minutes. You may need to add a splash of water if your sauce is on the thicker side.

Then, just Assemble The Sandwiches as instructed above! Easy as that!

Serve these Portobello Mushroom Sandwiches with these recipes:

Vegan Caesar Salad

Tomato Bisque

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