The trick to soft buns is minimal handling of the dough, long proving and setting them aside under a cloth to steam after they're cooked - plus a secret ingredient: instant mashed potato. Begin this recipe a day ahead to prove the dough.
- 1.4 kg coarsely minced beef
- 1 tbsp olive oil
- 300 gm Gruyère, coarsely grated
- 240 gm cheddar, coarsely grated
- To serve: lettuce leaves, tomatoes and Spanish onion
- 6 gm dried yeast
- 100 ml milk
- 600 gm bread flour
- 50 gm instant mashed potato
- 50 gm caster sugar
- 50 gm butter, softened
- 1 egg yolk, plus one extra whisked with 2 tsp water and a pinch of salt for eggwash
- For spraying: canola oil spray
- 450 ml white wine vinegar
- 130 gm caster sugar
- 30 gm sea salt flakes
- 8 jalepeños, thinly sliced
- 1For potato buns, combine yeast, milk and 100ml hot water in the bowl of an electric mixer fitted with a dough hook and stand until foamy (3-5 minutes). Add flour, sugar, butter, egg yolk, 1 tsp salt and 250ml water, and mix until just combined (3-5 minutes; do not overwork). Transfer dough to a lightly oiled bowl, cover with plastic wrap and refrigerate overnight to rest and prove. Knock back dough on a lightly oiled bench by gently gathering the sides and folding it back on itself, then rest again in a lightly oiled bowl covered with a damp tea towel (30 minutes). Gently knock back dough, divide into 8 balls, pulling sides of dough underneath to form smooth tops, then place evenly spaced on a large oven tray lined with baking paper. Spray liberally with canola oil and set aside until almost tripled in volume (1 hour). Preheat oven to 200C and place a small roasting pan half-filled with water at the base. Brush buns with eggwash, spray again with canola spray and bake until puffed, golden and cooked through (20-25 minutes). Set aside covered with a damp cloth to cool and steam.
- 2For pickled chilli, combine vinegar, sugar and salt, and bring to the boil in a saucepan. Add jalapeño chillies and set aside to cool.
- 3Preheat grill to high. Shape 170gm portions of beef into patties the same size as the buns and scatter with sea salt. Heat oil in a non-stick frying pan and cook the patties in batches, pressing occasionally to keep their shape, to medium-rare (10 minutes), transfer to an oven tray, top with both cheeses and grill until melted (2 minutes).
- 4Split buns and toast cut-side up under the grill. Spread aïoli over the bases and top with lettuce, tomato, Spanish onion, beef patties and tomato sauce. Serve with pickled chilli.