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4.72 from 7 votes

Shimeji Steak Sandwich with Dijon Soubaise Sauce

It’s salty, umami, crispy and the soubaise sauce will blow your mind. It’s a freakin’ VEGAN SHIMEJI STEAK SANDWICH!


For the Soubaise Sauce

  • 1 medium onion grated
  • 60 g vegan butter
  • 2 tbsp plain flour
  • 230 ml oat milk
  • salt and pepper
  • 2 tsp dijon

For the Sandwich

  • 2 large slices sourdough toasted
  • 1 white onion chopped through the centre into 1cm rings
  • 1 bunch shimeji mushrooms sliced in half
  • 1 tbsp dark soy sauce
  • 1 bulb baby bok choi


Make the Soubaise

  • In a small saucepan over a medium/low heat, add your vegan butter and allow it to melt. Add the grated onion and cook for around 5-7 minutes or until it is nicely caramelised.
  • Add the flour and allow to cook for a further 30 seconds, stirring constantly. Gradually add the oat milk a few tbsp at a time. Stir to combine and cook for a further minute to thicken. Season and stir in the dijon. Cover the pan and set aside.

Make the Fillings

  • In a small frying pan over medium heat, add the sliced onion along with a drizzle of olive oil. Cook for around 5 mins until nicely browned and caramelised. Remove from the pan and set aside.
  • Now add the two halves of shimeji mushrooms to the pan with another drizzle of olive oil. Using a smaller cast iron pan or a heavy pan lid, press down on the shimeji until they sizzle loudly (this helps to sear them and turn them nice and brown). Leave the cast iron pan/lid where it is and allow to cook for around 5 minutes. Remove the lid and add the soy sauce. Flip the mushrooms carefully, making sure not to break up the “steak”. Repeat the searing process on the other side for a further 5 minutes.

Assemble the Sandwich

  • Spread a layer of the soubaise on both sides of the toasted sourdough. Top with the onions, followed by the mushrooms and then the baby bok choi. Season, slice and eat!