In a large plate or wide bowl add the soy sauce, oyster sauce, 1 tbsp of vegetable oil, garlic and palm sugar. Mix until combined.
Place the steaks in the marinade and coat well on both sides. Use a fork to pierce over each side, to help the marinade soak in further. Season with salt and pepper, then cover and marinate for a minimum of 30 minutes (or overnight if marinating in advance).
Heat a cast iron pan (or cook over charcoal if you can) on high heat and coat with 1 tbsp of vegetable oil. Once hot, add in your marinated steaks and cook each side for 3-4 minutes for medium or 2-3 minutes for medium-rare. Seal the edges for 10-20 seconds each. You can flip the steaks more than once, whatever suits your style of cooking.
Transfer steaks onto a large plate. Cover with aluminium foil and rest for 10 minutes.
Once rested, use a large, sharp knife to slice into thin strips. Serve with your fresh Nam Jim Jaew dipping sauce and enjoy!
For the Nam Jim Jaew Dipping Sauce:
In a small bowl, add in the palm sugar, lime juice, fish sauce, toasted rice powder and crushed chilli powder. Mix until well combined.
Next pop in the chopped shallot and coriander/cilantro, stirring through slightly before topping up with water.
Skip the Marinade - Rub in olive oil and salt instead to save on marinating time.
Cook over Charcoal - For a more authentic taste, cook the steak straight over charcoal and infuse them with a smoky flavour alongside the marinade.
Dipping Sauce - If you’re pressed for time or can’t get fresh coriander or shallots, try it with Vietnamese nuoc mam cham (homemade or bottled). Or for a completely different flavour, try it with go for a sweet and savoury Japanese BBQ sauce (such as okonomiyaki sauce or takoyaki sauce).
Amp Up the Heat - Add more or less chilli flakes to suit your taste. Or add finely sliced bird’s eye chillies (small Thai red chillies) for an extra spicy kick!
Make it into a Salad - Add lettuce leaves, chopped tomato and extra coriander or mint, then spoon the dipping sauce over the top. Toss and serve!