How to Make It
In a large bowl, combine the beef, curry paste, sugar, and fish sauce and mix well. Cover and refrigerate for at least 8 hours or up overnight. Soak twenty-four 6-inch bamboo skewers in water to cover for 1 to 2 hours.
Cook a couple of pieces of beef in a small grillproof frying pan over medium heat or in a microwave, then taste them and adjust the seasoning with more fish sauce and sugar if needed, keeping in mind that the accompanying rice will be bland. The meat should taste salty and then a little sweet.
Divide the beef into twenty-four equal portions. Thread each portion onto a skewer.
Put the basil leaves in a small bowl and lightly mist them with water. Line a small plate with a paper towel. Place the bowl of basil, the towel-lined plate, and a small saucepan with a heatproof handle near the grill. Keep the leaves lightly misted. The moisture helps the leaves turn a bright, beautiful jewel-like green when they are fried. (Don’t overdo it, though, as the moisture can also cause splattering.)
Prepare a medium-high fire (400° to 450°F) in a charcoal grill using the two-zone method. Place the skewers on the hot side of the grill and cook with the lid off until you get some charring on the outside, 5 to 7 minutes. Move the skewers to the hold side of the grill, cover, and cook with the vents half-opened until no pink is visible in the beef, about 5 to 10 minutes.
About 5 minutes before the meat is done, in the reserved frying pan, combine the oil and turmeric (if using) and place it on the hot side of the grill. When the turmeric sizzles and the oil is turning yellow and is hot, drop 1 cup of the basil leaves into the oil and stand back. Within seconds the basil leaves will be crisp. Using a mesh skimmer, transfer them to the towel-lined plate and remove the pan from the grill.
To serve, transfer the skewers to a large platter. Drizzle some of the turmeric-and basil-infused oil over the beef. Top with the fried basil leaves and the remaining 1⁄2 cup fresh leaves. Serve immediately with the rice.