Beef Patties (French Bifteck Haché à la Lyonnaise)

Julia Child’s easy and elegant French hamburger.

Onions:
¾ cup yellow onion, finely minced
2 Tbsp. butter

Patties:
1½ lbs lean ground beef
2 Tbsp. butter, softened
1½ tsp. sea salt
⅛ tsp. black pepper, freshly ground
⅛ tsp. dried thyme
1 egg
½ cup flour, spread on a plate
1 Tbsp. butter
1 Tbsp. extra-virgin olive oil

Sauce:
½ cup beef stock, beef bouillon, dry white wine, dry white vermouth or red wine
2-3 Tbsp. butter, softened
2 Tbsp. green herbs, minced, such as parsley, chives, tarragon, or chervil

In a large skillet over medium heat, add the 2 Tbsp. butter and onions and cook slowly until soft but not brown, about 10 minutes. Transfer to a mixing bowl and set aside.

To the mixing bowl, add the beef, 2 Tbsp. softened butter, salt, pepper, thyme, and egg. Beat vigorously with a wooden spoon until well-mixed.

Form mixture into patties ¾" thick and cover and chill until ready to use.

When ready to cook, lightly roll patties in flour spread on a plate, shaking off excess.

In a skillet over medium-high heat, heat the 1 Tbsp. butter and oil. When it begins to foam and subside, sauté the patties to the desired temperature, about 2-3 minutes or more per side depending on doneness.

Transfer patties to a plate and keep warm while you work on the sauce:

Drain fat from skillet. Add liquid (stock, wine, etc) and let boil, scraping up bits from bottom of pan as it reduces. Cook down to almost a syrup consistency, then turn off heat, and add butter by ½ Tbsp. Swirl pan to melt butter, then stir in herbs.

Spoon sauce over hamburger patties and serve.