Whisk together curry paste, lime juice, fish sauce, grated garlic, coconut sugar, salt and black pepper. Add steak and turn to coat. Marinate in the refrigerator for at least 2 hours, but up to 8. 

Pat steak dry with a paper towel and heat a large skillet to medium high. Add 1 1/2 tbsp avocado oil, ghee or lard to the pan and cook steaks one at a time, flipping, until nicely charred on both sides but not cooked all the way through. If you have a meat press, now is the time to use it. The steaks will brown fairly quickly because of the sugar in the marinade, so make sure to flip them regularly. Remove first steak to a plate, sprinkle with a little salt, flip, salt the other side and repeat the whole process with the second steak. 

Set steaks aside to rest and prep ingredients for tacos. Do not throw away the liquid that is released on the plate from the steaks! You’ll use this later. 

Slice steaks in half lengthwise so that you have four equal sized pieces about 3 inches long. Slice each piece into 1/4 inch thick strips across the grain and add to a bowl. Add sliced jalepeno, green onions, cilantro, radishes, juice of half a lime and whatever cooking liquid has been released from steaks on the plate they were resting on. Toss and season to taste with salt if necessary.