Thinly slice the beef sirloin and chicken thigh fillets.

Place beef and chicken into separate shallow dishes.

Combine 1/2 cup coconut milk, 2 tbsp fish sauce, 3 tbsp sugar, chopped cilantro leaves, and curry powder in a bowl.

Mix until combined.

Pour the marinade over the beef and chicken, tossing to coat evenly.

Marinate in the refrigerator for at least 1 hour, or overnight.

Using a mortar and pestle, pound shallot, garlic, ginger, lemongrass, cilantro stalks, and chili with a little water to form a paste.

Heat peanut oil in a frying pan over high heat.

Sauté the paste for 1-2 minutes, until fragrant.

Stir in the remaining coconut milk and simmer for 5-6 minutes.

Stir in the remaining fish sauce and sugar, lime juice, and kecap manis.

Add the finely chopped peanuts and simmer for 4-5 minutes, until the sauce has thickened.

Preheat the grill to medium-high heat.

Thread the marinated chicken and beef onto skewers.

Grill the satays for 4-5 minutes per side, turning occasionally, until cooked through.

Serve the grilled satays with the peanut sauce, fresh cilantro leaves, and spicy fried rice.