Add rice to a small frying pan and gently toast over medium-high heat, stir occasionally for 3-5 minutes until the grains are toasted and golden. Leave to cool for a few minutes and then grind into a coarse powder using a mortar and pestle.
Steak
Heat a dry small frypan over high heat until it is very hot
Season steak with salt and pepper and drizzle with olive oil before placing into the searing hot pan
Cook on each side for 2-3 minutes for a medium steak, remove from pan and allow to rest
Dressing
Grind garlic and chillis into a paste with mortar and pestle, add lime juice, fish sauce and sugar, stir to combine. Taste and adjust accordingly
Assembly
In a large dish assemble lettuce leaves, vermicelli noodles, tomatoes and herbs. Thinly slice steak and place on top of the salad. Generously drizzle with dressing, sprinkle with toasted rice powder and scatter with pickled onions. Serve with a side of extra chilli and lime wedges.