Soak your chicken tenders in a mix of buttermilk, a splash of pickle juice or hot sauce, and a pinch of salt. Let it marinate for at least 30 minutes (or overnight).
In a shallow bowl, season your arrowroot or cassava flour with garlic powder, onion powder, paprika, cayenne pepper, sea salt, and black pepper.
Remove a tender from the buttermilk, press it into the seasoned flour, dip it back into the buttermilk quickly, and coat it a second time in the flour.
Melt your beef tallow in a heavy cast-iron skillet over medium heat until it reaches 350°F (175°C). Fry the tenders for about 3 to 4 minutes per side until they are an even, deep golden brown and reach an internal temperature of 165°F.