Ingredients: salt and freshly ground pepper, 2 teaspoons extra-virgin olive oil, plus more for brushing, 1 small red onion, halved and thinly sliced, 1 8-ounce package sliced mixed mushrooms, 1 egg, bread crumble, dry bread, to roll mushroom burgers, 1 tablespoon Worcestershire sauce, 2 teaspoons Dijon mustard
for serving: French potato salad with pickles
Methods: Soak dry bread in water.
Heat 2 teaspoons olive oil in a large skillet over medium-high heat. Add the onion and cook, stirring, 2 minutes. Add the mushrooms and cook 2 more minutes. Flavor with the Worcestershire sauce and mustard, cook until the vegetables are tender, about 2 more minutes. Season with salt and pepper and remove from the heat. Place mushroom mixture into a bowl, add 1 egg. Squeeze water from bread, add to mushrooms. Gently form 3/4 inch thick burgers and roll them in the bread crumble. Arrange burgers on the prepared pan and brush both sides with olive oil. Broil until browned, about 3 minutes per side.
Prepare French potato salad: Place potatoes in a large pot; cover with cold water by 1 inch and season generously with salt. Bring to a boil; reduce to a simmer and cook until potatoes are tender, about 15 minutes. Run under cold water to cool slightly, then drain.
Meanwhile, in a large bowl, whisk together oil, mustard, vinegar, shallot, parsley, dill and thyme; season with salt and pepper. Add potatoes and onion and toss to combine. Serve at room temperature.
Serve mushroom burgers with French potato salad and pickles.