Place sliced steak in a large bowl. Add the toasted sesame oil, 2 tbsp of the avocado oil, coconut aminos, coconut sugar, tapioca, Gochujang, salt and while pepper. Toss until the steak is very well coated.
Heat the remaining 1 tbsp avocado oil in a large skillet over medium-high heat. When the oil is hot, in batches, carefully place the sliced steak into a single layer in the skillet and cook until golden brown; about 2 minutes per side. Transfer cooked steak to a plate and continue to cook until all of your steak is ready.
Transfer the steak back into your skillet and add the kimchi. Toss until the kimchi is well combined with the steak and just warmed through, 2 more minutes.