Vegetarian Mushroom French Dip Sandwich Recipe

This vegetarian mushroom French dip sandwich, created by recipe developer Tanika Douglas, combines hearty portobello mushrooms with the sweet notes of caramelized onions, the salty creaminess of provolone cheese, and a rich, umami-packed shiitake jus. This sandwich elevates an everyday lunch or makes a delicious light dinner. Simple ingredients are crafted into a sandwich with punchy complementary flavors, ensuring it's as satisfying as it is easy to prepare. "Dip the portobello mushroom-laden baguette into the warm shiitake mushroom jus and prepare to be truly satisfied! The flavors work cohesively to create a warming, filling lunch or dinner," says Douglas. 

Whilst the French dip sandwich is traditionally made with meat, this meat-free version is equally flavorful, making it perfect for vegetarians and mushroom aficionados alike. Serving four, this sandwich is perfect for a family lunch or holiday gathering. The preparation is straightforward, taking just 20 minutes, while the cooking process requires another 45 minutes to let the flavors meld and develop. 

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. 

Cut the mushrooms into ¼-inch slices.

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

Cook onions for 25 minutes, stirring intermittently or until caramelized.

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

Spoon the onions into a bowl to use later.

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.

Remove mushrooms from the pan and set aside.

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

Add the white wine and cook for one minute to deglaze the pan, and evaporate the alcohol.

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

Remove the shiitake mushrooms from the pan, along with some of the liquid and place into a blender. Process until perfectly smooth.

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

Slice each baguette into two pieces and then halve each piece lengthways, allowing the lid to remain attached.

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

Place the sandwiches back under the broil for one minute to melt the cheese.

Pour the jus into individual ramekins.

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

French dip sandwiches, including this vegetarian mushroom French dip sandwich, can be prepared in advance, but there are some important considerations to keep in mind to ensure they maintain their quality and rich flavor. Douglas says "While the individual components of the sandwich, such as the caramelized onions, sauteed mushrooms, and shiitake jus, can be made days ahead and stored separately, it's best to assemble the sandwiches just before serving to maintain the texture and prevent sogginess." The baguettes, in particular, are best left uncut until right before eating to keep them fresh and crisp. Simply reheat the mushrooms, onions, and jus, build the sandwiches, and broil to melt the cheese as directed. This ensures the sandwiches remain moist and flavorful. 

If you would like to have the finished components on hand for when hunger strikes, freezing is a brilliant option. Place the cooked mushrooms, caramelized onions, and shiitake jus into separate freezer bags or airtight containers and freeze for up to six months. When ready to eat, allow each component to defrost, reheat until warm, and continue with the recipe as directed. This way, you can enjoy the convenience of a make-ahead meal without compromising on the sandwich's umami flavor.

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.