In a mixing bowl, combine ¼ cup of soy sauce, 2 tablespoons of sesame oil, 2 minced garlic cloves, 1 tablespoon of grated fresh ginger, 1 tablespoon of brown sugar, and freshly ground black pepper to taste. Whisk until well blended.

Place steak in a large resealable bag or dish, pour marinade over the steak, ensuring all surfaces are coated. Refrigerate for at least 1 hour.

While the steak marinates, wash and chop your mixed vegetables into bite-sized pieces.

Preheat your grill to medium-high temperature (around 400°F). Add 1 tablespoon of vegetable oil to prevent sticking.

Remove steak from the refrigerator and let excess marinade drip off. Place on the hot grill, cooking for 3-5 minutes per side.

Once grilled, transfer the steak to a plate and let it rest for about 5 minutes.

Add the remaining tablespoon of vegetable oil to the grill, followed by your chopped vegetables. Grill for 4-5 minutes, tossing occasionally.

Slice the steak thinly against the grain into strips.

Arrange the sliced steak and grilled vegetables on a serving platter. Drizzle some of the remaining marinade over the top.

Garnish with chopped green onions and a sprinkle of sesame seeds.