French Onion Cheeseburger

• масло↗2 tbsp tbsp
• олія1 tbsp tbsp
• цибуля↗1

  тонко нарізана

• м'який світло-коричневий цукор↗½ tbsp tbsp
• яблучний оцет↗1 tsp tsp
• цільнозернова гірчиця↗1 tbsp tbsp
• яловичі котлети2
• груйєр↗2 slices
• булочки бріош↗2
• крес↗2 handfuls

Step-by-step instructions

1. 1

   Place butter and oil in a large non‑stick pan. Add the onion and fry over medium heat for 15 minutes until golden and sticky. Add the soft light‑brown sugar, apple cider vinegar and whole‑grain mustard, stir. Heat the grill to medium‑high. Lay the beef patties on a tray and grill each side for 5‑8 minutes until done. In the last minute place Gruyère on the patties and grill until melted. Lightly toast the brioche buns. Assemble the buns with the patties, then the sticky onions and distribute the rocket between portions.