In a large bowl, mix the marinade ingredients. If using the lemongrass stalk without removing the outer layers, process it in a blender. Otherwise, finely chop it
Submerge the chicken cutlets, making sure each piece is well coated. Let the chicken marinate for at least 12 hours in the refrigerator to allow the flavors to fully penetrate the meat
Prepare the skewers
30 minutes before you are ready to grill, submerge your bamboo skewers in water. This is crucial to prevent them from burning on the grill.
Once the chicken has marinated and the skewers have soaked, thread the chicken onto the skewers.
Grill the chicken
Heat the grill or griddle over medium-high heat. It should be hot enough to sear the chicken without burning it.
Place the skewers on the grill and cook for about 2 to 3 minutes on each side, turning regularly. The chicken is ready when it is firm to the touch, reaches an internal temperature of 74°C, and the juices run clear.
Thai satay sauce
Roast the peanuts and lightly crush them with a mortar and pestle.
Process the garlic and shallots in a blender.
Place a saucepan over medium heat and add the oil. Add the blended garlic and shallots and cook until fragrant.
Add the massaman curry paste and cook for about 2 minutes.
Stir in the coconut milk, peanut butter, soy sauce, tamarind sauce, palm sugar, and salt. Cook until the palm sugar has dissolved and the mixture returns to a boil.
Add the crushed peanuts and continue cooking for a minute or two before removing from the heat.
Notes
Yes, I know, 12:00 of marinating time might sound like a deal-breaker. And yes, you can cut that down to a few hours, or even 10 minutes... But honestly, the thinly sliced chicken pieces absorb the flavors so well that it would be a crime not to plan a little ahead.