Ingredients
Method
- Mix sauce ingredients, chill.
- Caramelize onions in butter + oil with salt, 20–25 mins.
- Form 8 thin patties, season, cook. Spread mustard before flipping. Add cheese, stack 2 per burger.
- Build burger: sauce → tomato → lettuce → patties → onions → sauce → top bun.
- Cook fries, top with cheese, onions, and sauce.
