Thinly slice beef across the grain at a 45 degree angle; set strips aside.
I used lemongrass paste from the tube as it works easier for me, but you can use chopped.
If you do use the chopped, place it in the food processor (small bowl if you have that) along with the garlic, galangal, and onion; pulse into a thick paste, adding the lime juice and oil through the chute.
You could also grind this in a mortar but it's more work.
You could also use fresh turmeric but it stains your equipment, especially the food processor (so I advise not to).
After you get the paste together, stir in the ground turmeric in a stainless steel bowl (emphasis on stainless or glass).
Toss the marinade with the beef sticks to coat completely and marinate overnight.
I also soak wooden skewers overnight , weighing them down under cool water with a plate. You can use metal skewers if you like.
Thread up the beef onto the skewers.
Prepare grill and grill over moderate heat (three second rule) on an oiled grate until cooked through and lightly charred. Note that the thin slice and cut of beef should keep it where you can cook this well done without being tough (sort of like fajitas).