French Onion Soup Burgers
If you love French onion soup (or really just bread, cheese, and wine - and well, onions) then you’re going to LOVE this. I didn’t think French onion soup could get very much better or that there was a need for it to, but this burger proved me wrong.
I don’t know why, but when I think French onion soup, I think mushrooms — after onions, obviously — and vice versa. I know mushrooms aren’t in French onion soup, but it’s like they live in the same vacinity of earthy flavors. When I was brainstorming burger ideas with a mushroom/beef patty, I immediately thought of French Onion Soup.
Funny story though: My dad came home from playing golf the day I first made these. Neither my mom nor I were in the kitchen, and I guess he saw a burger in the fridge - assuming it wouldn’t have mushrooms in it, as most would - and he ate it.
Later that night, my dad turned to me and said, “Those burgers you made were incredible!”
A sigh of relief first rushed over me. Sometimes it’s nice to have a little more approval of something than just my own opinion. Then I thanked him, not realizing he had tried them. A few minutes later, it dawned on me, he had eaten mushrooms. And he liked it. I nearly died laughing and broke the news to him, to which he was very disturbed and disgusted by.
My dad hates mushrooms. It was great.
I think I might have shown him the unearthly light that eating fungi is.
Really though, you’ve heard it from a mushroom-hater yourself that this burger is, and I quote, “incredible.” So if you hate mushrooms, don’t run away yet.
All the mushrooms do is make the burgers JUICY and add a little extra hidden dose of veg.
French Onion Soup Burgers
Roughly 6 burgers
For the patty:
10 oz white button mushrooms, washed and stemmed
24 oz ground chuck
2 tbs. butter
1 tsp. Salt and pepper
For the onions / sauce:
1/4 cup red wine + 1/3 cup red wine, separated
1/4 cup beef stock + 1/2 cup beef stock, separated
1 tbs. olive oil
2 tbs. butter
1 sweet onion, thinly sliced into half circles
1 garlic clove
1 ts. black peppercorns
2 thyme sprigs
For the aioli:
2 egg yolks
2 garlic cloves
2/3 cup extra-virgin olive oil
Juice of half a lemon
1 tsp. dijon
1/2 tsp. salt, 1/2 tsp pepper
For the assembly:
French baguette
Arugula
Gruyère cheese
Finely dice the mushrooms to create pieces a similar size to ground beef. In a skillet, heat the 2 tbs. butter for the patty over medium-high heat until just melted. Once melted, add in the mushrooms and stir to coat. Cook for about 5 minutes, or until the mushrooms are softened and wilted down. Finish with the salt and pepper, stir, and set aside to let cool.
While the mushrooms are cooling, prepare the aioli and the onions.
For the aioli, add the egg yolks, garlic, dijon, lemon juice, salt, and pepper into a food processor. Blend until finely mixed, 30 seconds to 1 minute. Keep the food processor on and slowly pour a thin stream of olive oil into the food processor to create an emulsion. If pouring slow enough, this should take about 2 minutes. Once the oil is gone and the aioli is thickened, taste for seasoning and store in the fridge until time to assemble the burger.
For the onions, heat 1 tbs. olive oil over medium-high heat. Add the onions once the oil is hot (it should sizzle!) and let cook until slightly softened and caramelized, stirring occasionally. Once caramelized, deglaze the pan with 1/4 cup each red wine and beef stock. Stir until all liquid is cooked down and the onions are completely softened. Remove the onions, and over, high heat, add in the 1/3 cup red wine, 1/2 cup of beef stock, garlic clove, black peppercorns, and thyme sprigs. Bring to a small boil and then turnt to a simmer to reduce. Once slightly thickened, turn off the heat and melt in the 3 tbs. butter. Remove the thyme sprigs, peppercorns, and garlic clove, then set aside.
Mix the cooled mushroom mixture with the ground chuck until thoroughly combined and form into patties roughly 4 inches in diameter. Heat a cast iron skillet over high heat, with no oil. Once heated, add in 1 tbs. vegetable or olive oil, and the patties, ensuring to have at least 2 inches of space between each patty. Cook for 3 minutes on each side. Then, trap the burgers with a plate, bowl, or cover, and allow the burgers to steam for another 2-3 minutes (this creates a super juicy burger), until the patties are medium and light pink in the center, with an internal temperature of at least 155º.
To assemble, cut and toast a piece of a French baguette to fit the burger patty. Spread each side with aioli. Top the burger patties with a few slices of gruyère cheese. Either torch or broil the cheese to melt and slightly toast the cheese. Place on the bottom piece of the bread. Layer with the caramelized onions and fresh arugula. As you eat, dip into the red wine-beef stock sauce.
