Step 1

Place chilli, lemongrass, ginger and garlic in a food processor and whiz into a paste. Add palm sugar, lime juice, fish sauce and 1 tablespoon oil and whiz to combine. Toss the beef in a bowl with half the marinade. Chill for 15 minutes.

Step 2

Meanwhile, cook the vermicelli according to the packet instructions. Drain, refresh under cold water and toss with remaining marinade.

Step 3

Heat 2 teaspoons oil in a wok or large pan over medium-high heat. Add half the beef and cook, turning, for 5-7 minutes, or until browned. Repeat with remaining 2 teaspoons oil and beef. Keep warm.

Step 4

Toss spring onions and herbs with the rice noodles, then top with the beef and serve.