Pat dry steak with a paper towel and generously sprinkle salt on both sides of the steak. Note - we recommend letting the steak sit at room temperature for 20-30 minutes after seasoning for even cooking and letting the seasoning settle.
Grate garlic with a grater or a garlic press, grate daikon and set aside.
In a stove top pot, add dashi, soy sauce, sweetener, grated garlic and Japanese sake. Bring sauce to a boil then remove from heat and place in refrigerator until ready to pour.
Add neutral oil into a cast iron pan on high heat until up to temp. Once up to heat, place the steak inside the pan and cook each side for 1-2 minutes to sear. Note - Don't move or lift up the steak while searing.
After searing both sides, transfer the entire pan into the oven. Cook the steaks in the oven based on the doneness chart above. Note - times will vary depending on the exact cut and thickness.
Let the steak rest for 5 minutes then cut into slices.
Transfer sliced steak onto a serving plate, pour sauce over, and top with grated daikon and radish sprouts. Serve at either room tempeture or slightly chilled.