Garten grinds together fatty sirloin and chuck steak with egg yolks, steak sauce, salt, and pepper. The egg yolks add moisture, richness, and hold the patty mixture together.
Steak sauce adds even more moisture and a robust flavor profile. To make the burgers even better, Garten adds a pat of butter to the patties as they cook for a sweet, juicy bite.
Beyond adding these ingredients, Garten finishes the recipe by letting the burgers rest for 5 minutes before assembling and eating them. This keeps the meat's juices locked in.