In a mixing bowl, whisk together brown sugar, fish sauce, garlic, onion, oil, soy sauce, coriander, ginger, cumin, turmeric, and Calabrian pepper until smooth.

Cut beef tenderloin tips into strips about 2 ½ inches long and ⅛ inch thick. Stir the beef into the marinade until it is completely coated, about 1 minute. Cover the bowl with plastic wrap and marinate in the refrigerator for 2 to 4 hours.

Preheat an outdoor grill for high heat. Lightly oil the grate.

Remove the beef from the marinade and shake off any excess marinade. Thread ¼ of the meat onto each metal skewer. Discard the remaining marinade.

Arrange skewers on the preheated grill; cook until the meat stops sticking to the grill, 1 to 2 minutes. Flip the skewers and continue cooking until the meat is well browned and shows grill marks, 2 to 2 ½ minutes. Flip the skewers again; cook until the meat is still slightly pink, about 2 minutes. Transfer the skewers to a platter; let them rest for 2 minutes before serving.