Do restaurants still have French dip sandwiches on the menu? I remember back in high school or college eating them when dining out, but don’t recall seeing them on menus after that. Maybe I just didn’t notice once I became a vegetarian.
When I saw a mushroom version online recently, warm food memories of the traditional sandwich came flooding back. The chewy roll, the tender beef, and oh, the au jus! Honestly I don’t remember cheese and caramelized onions on the sandwich, but what I ate probably wasn’t authentic, and I’m sure it would have been loads better with those two additions.
Since my go-to beef replacement over the last almost 30 years has been mushrooms in some form, this moved to the top of my “must make” list. Truly a multi-dimensional meal, the bite of horseradish in the garlicky mayo; the rich, meaty mushrooms; the soft, sweet caramelized onions; creamy Provolone; and the complex au jus come together on toasty French bread for a sensory overload of deliciousness. When Pete deemed this one of the best things I’ve ever made, well, I felt a duty to share. You’re welcome!
Mushroom French Dip with Horseradish Mayo
Horseradish Mayo:
½ cup of your favorite mayonnaise (if you’re mayo averse, I highly suggest Vegenaise Better than Mayo brand—no eggs, no dairy)
2 teaspoons prepared horseradish
2 cloves garlic, finely grated
Pinch of salt
Seasoned mushrooms:
6 large portabella mushroom caps or more if they’re smaller (about 18 ounces total), wiped clean, gills scraped off, and sliced about 1/3 inch thick
3 tablespoons extra-virgin olive oil
2 teaspoons Montreal steak seasoning (store-bought or homemade; I made a scaled down version of this recipe) or just use salt & freshly ground black pepper, to taste
Caramelized onions and au jus:
2 tablespoons unsalted butter
1 large sweet onion, halved and thinly sliced
¼ cup dry sherry
1 tablespoon Worcestershire sauce (Annie’s and Whole Foods 365 are both vegetarian)
1 tablespoon reduced sodium tamari or soy sauce
2 cups vegetarian “beef” broth (I used 2 teaspoons Better than Bouillon No Beef Base with 2 cups hot water)
Salt & freshly ground black pepper, to taste
To complete the sandwiches:
4 demi baguettes or one long baguette cut into four sections
Butter or buttery spread, optional
Provolone cheese slices
To make horseradish mayo, whisk ingredients together in a small bowl. Cover and refrigerate until ready to use.
To prepare the mushrooms, warm the olive oil in a large, heavy skillet over medium heat. Add the sliced mushrooms and sprinkle with steak seasoning. Cook, tossing mushrooms occasionally, until they release their liquid, it has cooked off, and mushrooms are tender, about 10-15 minutes. Set aside.
To caramelize the onions and make the au jus, melt the butter in a heavy skillet, preferably cast-iron, over medium heat. Add onions and cook, tossing occasionally, until softened, about 5 minutes. Reduce heat to medium-low and continue cooking, stirring occasionally, until they are golden brown, about 30-40 minutes.
Preheat oven to 450 degrees F.
Add the sherry to the onions and cook until the sherry has evaporated. Add the Worcestershire, tamari, and the broth. Increase heat to medium and bring to a simmer. Continue to simmer for 5-10 minutes until slightly reduced. Taste, and add salt and freshly ground black pepper, to taste.
Place a fine mesh strainer over a bowl and dump the mixture into the strainer, separating the onions from the au jus. Set both aside.
Halve the baguettes horizontally and spread with butter (optional). Place on a sheet pan. Divide mushrooms among bottom bread sections and cover with Provolone slices (cut to fit if slices are wide). Transfer pan to the oven and toast the open sandwiches for about 5 or 6 minutes.
Remove from oven and top the mushroom/cheese side of sandwiches with caramelized onions. Liberally spread top sandwich portions with the horseradish mayo and put sandwich tops on bottoms. Serve each sandwich with a small bowl of au jus for dipping. Make sure to have plenty of napkins and enjoy! Makes 4 sandwiches (no judging if the two of you eat all four portions; that might have happened here).
Finding my Inner Chef 