The Krug Onion Burger
by Simon Davies

For the caramelized onions

2 each yellow onions, thinly sliced

4tbsp (60g) butter

1 bottle champagne

For the Champagnnaise

1 each egg yolk

150g grapeseed or other neutral oil

30g dijon mustard

30g cornichons, finely chopped

8g chives, thinly sliced

10g champagne

4g salt

1/2g (16 cracks)  black pepper

For the rest

4 each 1/4lb burger pattys, preferably 80/20 beef

4 each brioche buns

2tbsp (30g) butter

4 slices of American cheese

Fries, optional
 

For the caramelized onions

Add the butter to a large pan over medium-high heat followed by the onions.  Stir frequently to insure even color.   Once they start to caramelize, deglaze with some champagne to help soften them and add some sweet champagne flavor. Reduce, let the onions caramelize more and repeat until the onions are well caramelized and dark brown. Set aside.

For the Champagnnaise

Add the egg yolk and dijon mustard to a medium bowl and, while whisking, slowly emulsify the oil a little bit at a time.  Once all the oil is incorporated and you have a thick emulsion add the other ingredient and fold in.

For the rest

Salt and sear the burger pattys on a griddle or pan over high heat melting the cheese and grilled onions to the top in the last few minutes of cooking.

Spread butter on the inside of the brioche buns and toast in the pan or under a broiler.  Spread each side of all four buns with a generous amount of champagnnaise. Assemble with the patty, cheese, and onions and serve.