Grind together the dried red chili flakes, fennel seeds, kosher salt and Sichuan peppercorns, then add the cumin and garlic powder, and combine thoroughly.
Set aside 1 tablespoon of spice mix, to be sprinkled onto the skewers as they're being grilled.
Cut the duBreton Pork Boneless Filet into 1 inch cubes and place in large mixing bowl, add in the spice mix, vegetable oil and Chinese cooking wine. Mix and make sure each piece of pork is coated on all sides.
Let the marinated pork rest in the fridge for 30 mins.
Preheat BBQ on medium heat and lightly oil grates.
Thread pork pieces onto skewers, packed loosely.
Grill skewers on BBQ over indirect medium heat for 4-6 mins per side, then finish on direct high heat until pork is no longer pink inside, 2-3 mins per side. Let the skewers rest for 5-10 mins before serving.
If using bamboo skewers, soak them in water for over 2 hours to prevent the ends from burning on the BBQ
To thoroughly combine spice mixes, put all your ingredients into a jar with a lid and shake vigorously. This also allows you to make a large batch of spice mix and to easily store for next time.