Make the Teriyaki Sauce: Combine Mirin, rice wine, sugar, and soy sauce in a saucepan. Heat over medium heat until the sugar dissolves. Remove from heat and let cool. Reserve some sauce for serving.
Step 2
Prepare the Grill: Preheat your grill to high heat, preferably using charcoal for an authentic Japanese char-grilled flavor.
Step 3
Prepare the Scallions and Tomatoes: Slice 1-inch pieces of the white stem of the scallion and thread these and the cherry tomatoes separately onto skewers.
Step 4
Skewer the Steak: Thread the beef cubes onto bamboo skewers, leaving enough space between each cube for even cooking.
Step 5
Baste the Steak: Brush or dip the beef skewers in the teriyaki sauce, ensuring each cube is coated.
Step 6
Grill the Steak: Place the skewers on the grill over direct high heat. Cook for about 2-3 minutes per side, or until browned and cooked to your desired doneness. Brush with more teriyaki sauce halfway through cooking.
Step 7
Grill the Tomatoes: Grill the cherry tomato skewers alongside the steak.
Step 8
Rest and Serve: Remove the steak and tomato skewers from the grill and let them rest for a few minutes. Garnish the steak skewers with chopped scallions and serve with the reserved teriyaki sauce. Serve the grilled cherry tomato skewers alongside.