French Onion Portobello Burgers Recipes

3-INGREDIENT FRENCH ONION BURGERS

Steps:

• Prepare the grill for medium-high direct grilling, 450-500 degrees F. Prep any toppings & condiments as desired (see below).
• Add the ground beef, onion soup seasoning mix, Worcestershire sauce & kosher salt to a large mixing bowl. Using your hands, mix just until well combined. Be careful not to overmix as it yields a dryer, tougher burger. Divide the mixture into 4 equal portions. Press each portion into a 1-inch thick burger patty. Use your thumb to press a slight indent in the center of each burger patty.
• Place the burger patties on the grill grates, directly over the flame. Grill 3 minutes per side for medium doneness. If you prefer a less/more done burger, grill for 1 minute less/more. If making a cheeseburger, add the cheese to the burger patties in their last minute of grilling. Toast the St Pierre Brioche Burger Buns while you're at it - see below!
• Build your burgers as desired. At our house, the toasted St Pierre brioche buns get a quick schmear of Dijonnaise, topped with leafy lettuce, a French onion burger, crispy bacon, & caramelized onions. Serve immediately. Enjoy!

FRENCH ONION PORTOBELLO BURGERS

Steps:

• Preheat the broiler. Line a rimmed baking sheet with aluminum foil.
• Melt the butter in a medium skillet over medium-low heat. Add the sliced onions, 1 tablespoon fresh thyme or 1 1/2 teaspoons dried, 1/2 teaspoon kosher salt and a few grinds of pepper. Cook, stirring occasionally, until the onions are deep golden brown and caramelized, about 15 minutes. If the skillet gets too brown, add 2 tablespoons water and scrape the brown bits from the bottom of the skillet with a wooden spoon; continue to cook until all the water has evaporated. Add 1 tablespoon of the Worcestershire and stir until completely absorbed, about 1 minute more.
• Meanwhile, place the muffins or buns on the prepared baking sheet and broil until toasted and browned along the edges, 1 to 2 minutes. Set aside for serving.
• Put the mushroom caps, gill-side up, on the same baking sheet. Broil until they release their juices and soften slightly, about 6 minutes. Flip the mushrooms, brush the tops with the oil and season with the garlic salt. Broil until lightly browned and the juices have cooked off, about 6 minutes more. Top each mushroom with 1/4 cup cheese, then return to the broiler until the cheese melts, 1 to 1 1/2 minutes.
• While the mushrooms are broiling, stir together the mayonnaise, garlic, remaining 1 teaspoon fresh thyme or 1/2 teaspoon dried thyme and 1 teaspoon Worcestershire in a small bowl until smooth. Season with a pinch of kosher salt and pepper. Spread on the inside of the toasted muffin or bun tops. Place 1 portobello mushroom on each muffin or bun bottom. Layer with the caramelized onions and crispy fried onions, then close the burgers and serve.

STUFFED FRENCH ONION SOUP BURGER

Steps:

• For the onion jam: Heat a large saute pan, then toss in the onion and garlic slices with 2 tablespoons oil and a generous pinch of salt. Cook over medium heat for 2 to 3 minutes, then add the Marsala, brown sugar and mustard and cook, stirring occasionally, until the onions are caramelized and tender, 20 to 25 minutes. (Do not rush this step, because properly caramelized onions make this burger top-notch!) Stir in the vinegar and cook to blend in, 1 to 2 minutes. Set aside.
• For the burgers: In a medium bowl, break up the meat and spread it up on the sides of the bowl so that the seasoning really permeates. Sprinkle the meat with salt and pepper. Gently mix in the Marsala, soy sauce and Worcestershire. Do not overmix. (The more you work the meat, the tougher the burger.) Form the meat into 4 even patties that are about 3/4-inch thick and transfer to a baking sheet.
• Use a spoon to gently scoop out a little meat and make a hole or pocket in the center of each patty that does not go all the way through to the bottom. Place about 1/4 cup Gruyere in the hole of each patty. Flatten the piece of meat you scooped out and press it over the cheese so that it's hidden in the middle of the patty. Turn the patty on the other side that it is weighing down on the seam. Repeat with the remaining patties. Refrigerate for at least 30 minutes and up to 6 hours.
• Preheat the oven to 400 degrees F.
• Heat a large skillet over medium-high heat and add the remaining 4 tablespoons oil. Sprinkle the patties lightly with salt. When the oil begins to smoke lightly, arrange the patties in a single layer, cheese-pocket-side down, at a distance from one another. Cook the patties, undisturbed, until the bottom browns, 3 to 5 minutes. Turn the patties on their other sides and let the bottoms brown again, 3 to 5 minutes. Lower the heat and add the stock to the skillet and cover. Cook on low heat until the patties are cooked through, 8 to 10 additional minutes. Remove the cover, shut off the heat under the skillet and let the patties rest with the heat off.
• Arrange the bun halves in a single layer on a baking sheet and sprinkle each bun half with about 1/4 cup Gruyere. Place the baking sheet in the center of the oven and toast until the buns are golden brown and the cheese is bubbling and melted, 5 to 8 minutes. Season with salt and pepper.
• Arrange the bun bottoms on a flat surface. Mix the onion jam and remaining cup Gruyere into the liquid in the skillet. Taste for seasoning. Spoon some of the onions and liquid on each bun bottom and top with the patties and more onions. Top with a few slices of pickle and season the bun tops with a pinch of salt. Close the burgers and serve.