Shaking Beef Steak Frites with Lime-Pepper Butter (Vietnamese × French)

Method

1. Peel the potatoes, cut into 1 cm sticks and put them in cold water. Cut the beef into 2.5 cm cubes, pat dry and toss with most of the minced garlic, the oyster sauce, soy sauce, sugar and part of the pepper. Leave the potatoes soaking and the beef in the fridge for 30 min.

   Add in this stepFloury potatoes 400 gBeef sirloin or rump steak 300 gGarlic cloves 1¾Oyster sauce 1 tbspSoy sauce 2 tspSugar 1 tspCoarsely ground black pepper ½ tsp

2. Lime-pepper butter: mash the soft butter with the rest of the garlic finely grated, the lime zest plus 1 tsp of its juice, the fish sauce and the remaining pepper. Roll it into a log in cling film and chill until firm. Cut the rest of the lime into wedges.

   Add in this stepButter, softened 30 gGarlic cloves 1¼Lime 1Fish sauce 1 tspCoarsely ground black pepper ¼ tsp

3. First fry: dry the potatoes completely with kitchen paper (any water makes the oil spit). Fill a 20 cm deep pot no more than one-third full with oil and heat on medium heat to 160 °C. Fry the chips in small batches, 5 min per batch, until soft and cooked but still pale, then lift out.

   Add in this stepOil for deep-frying 1,000 ml

   medium heat

4. Second fry: turn up to medium-high heat and bring the oil to 190 °C. Fry the chips again in batches, 2 min 30 sec per batch, until golden and crisp. Drain on kitchen paper and salt straight away. Never leave hot oil unattended; if it catches fire, don't use water: cover with a lid and turn off the heat.

   Add in this stepFlaky salt ½ tsp

   medium-high heat

5. Heat a cast-iron pan on high heat until smoking, add the searing oil and cook the beef in a single layer in 1 batch(es), 2 min 30 sec per batch. Leave it for 1 minute, then shake the pan to roll the cubes until deep brown outside and pink inside.

   Add in this stepNeutral oil (for searing) 1½ tbsp

   high heat

6. Spread the watercress on plates, top with the beef and lay thick slices of lime-pepper butter over the hot meat so they melt. Serve at once with the chips and lime wedges.

   Add in this stepWatercress 60 g