In a mixing bowl, combine soy sauce, brown sugar, vegetable oil, garlic, ginger, coriander, turmeric, and cayenne pepper to prepare the marinade.

Add the sliced beef to the marinade, ensuring all pieces are well coated. Let it marinate for at least 20 minutes.

If using wooden skewers, soak them in water for about 30 minutes.

In a small bowl, whisk together peanut butter, coconut milk, lime juice, and a pinch of salt to prepare the peanut sauce.

Preheat your grill or grill pan over medium-high heat.

Thread the marinated beef onto the soaked skewers, leaving a little space between each piece.

Place the skewers on the grill and cook for about 3-4 minutes on each side.

Once cooked, remove the skewers from the grill and serve them hot with the peanut sauce.