This is one French variation on the hamburger. Another, called bifteck haché à cheval—or chopped steak on horseback—is so named for the fried egg "cowboy" perched atop the beef.
So how was it? I thought it was a bit much, sort of a hamburger dressed in a tuxedo. I think it’s far too rich in taste for the average American. I’m a large man and a big eater and I thought that one of these, made with perhaps less than a quarter pound of beef was too much.
Anyway, it’s a fun item to try.
10 tbsp. butter, softened
1 medium yellow onion, peeled and finely chopped
1 1⁄2 lb. ground beef or chuck
Leaves from 1 small sprig fresh thyme, chopped
1 egg, lightly beaten
Salt and freshly ground black pepper
1⁄2 cup flour
1 tbsp. vegetable oil
1 shallot, peeled and minced
1⁄2 cup red wine
Leaves from 6 sprigs parsley, chopped
Melt 2 tbsp. of the butter in a medium skillet over medium heat. Add onions and cook, stirring often, until soft, about 10 minutes. Transfer onions to a large bowl and set aside to cool. When cool, add meat, thyme, egg, 2 tbsp. of the butter, and salt and pepper to taste and beat with a wooden spoon until well combined. Divide meat mixture into 6 equal parts, then shape each into a 3 1⁄2" patty. Put flour into a dish, dredge patties, shaking off excess, and set patties aside.
Heat oil and 1 tbsp. of the butter together in a large heavy skillet over medium-high heat. Add patties and sear until well browned on both sides, turning once, 2-3 minutes per side for medium rare. Transfer patties to a warm platter and loosely cover with foil.
Increase heat to medium-high, add wine, and cook, scraping browned bits stuck to bottom of skillet with a wooden spoon, until reduced by three-quarters, about 2 minutes. Remove skillet from heat and add the remaining 4 tbsp. butter, 1 tbsp. at a time, stirring constantly, until butter is melted and sauce is thick and velvety, about 1 minute. Add parsley and season