Preheat grill for high heat and lightly oil the grate. Lightly oil steaks with vegetable oil.
Stir soy sauce, rice vinegar, horseradish, cherry tomatoes, and hot chile paste in a bowl until well combined. Leave it for 20 minutes.
Place steaks over hottest part of the grill and cook for 3 minutes per side. Transfer to a plate. Spoon soy sauce mixture over steaks and garnish with green onion.