Vegetarian Mushroom French Dip Sandwich Recipe

This vegetarian mushroom French dip sandwich boasts a harmonious medley of ingredients. Douglas offers, "At its core are the portobello mushrooms, sauteed in olive oil, which take center stage with their robust, meaty texture and a deep umami flavor that beautifully mimics traditional French dip fillings."

To enhance the sandwich, caramelized onions are intensified by a touch of brown sugar and balsamic vinegar. The rich shiitake jus, which is made from butter, garlic, white wine, dried shiitake mushrooms, vegetable stock, thyme, salt and pepper, provides a warm, rich, umami depth to the dish. Provolone cheese melts over the mushrooms. The baguette delivers a crunch on the outside and a soft, chewy interior to mop up the jus. Though the provolone cheese and butter add richness and flavor to the dish, they can be easily substituted for plant-based alternatives if desired. 

Place a skillet over medium-low heat and add 2 tablespoons olive oil and onions.

Stir in the brown sugar and balsamic vinegar. Continue to cook for five minutes or until the sugar has dissolved.

Turn up to medium-high heat and add 1 tablespoon olive oil and sliced portobello mushrooms to the same pan you cooked the onions in and cook for seven minutes or until dark golden and caramelized. Flip intermittently.

Add the butter and garlic to the pan and cook for two minutes or until the garlic is fragrant.

Add the dried shiitake mushrooms, vegetable stock, thyme, salt and pepper, and simmer for five minutes.

Pour the shiitake puree back into the pan and stir in. Cover the jus to keep warm and turn off the heat.

Spread a spoonful of caramelized onions onto each bun, then top with the portobello mushrooms and the provolone cheese slices.

Place the sandwiches onto their serving places, close the lids, and place the individual jus ramekins alongside to serve.

The origins of the French dip sandwich are steeped in culinary controversy, with two Los Angeles restaurants, both dating back to the early 20th century, claiming the creation. The most widely accepted story attributes the sandwich's invention to Philippe Mathieu, the founder of Philippe The Original. Allegedly, in 1918 Philippe accidentally dropped a French roll into a roasting pan filled with jus (juices from roasting meat) while preparing a sandwich for a police officer. Instead of throwing it away, he served the sandwich to the officer, who thoroughly enjoyed it. This serendipitous event resulted in the French dip, a flavorful sandwich often filled with thinly sliced roast beef and served with a side of jus for dipping. However, another restaurant, Cole's, also claims to have introduced the French dip around the same time at the request of a customer with sore gums who wanted the bread softened. The exact origin story remains contested by the rivaling restaurants. 

Whilst the original recipe uses cooked sliced beef with a jus made from the roasted beef juices, this version celebrates the portobello mushroom and transforms this crowd favorite into the perfect vegetarian lunch. Regardless of its exact beginnings, there's no doubt that the French dip has become a classic comfort food enjoyed by sandwich enthusiasts worldwide.