Step-by-step instructions:

Marinate the Beef: Place thinly sliced beef in a bowl with ½ cup teriyaki sauce. Marinate at least 30 minutes.

Sear the Beef: Heat 1 tbsp oil in a large non-stick skillet over medium-high heat. Remove beef from marinade, let excess drip off, and sear 3–4 minutes per side until browned. Set aside.

Cook the Rice: Add rice to the pan with remaining oil and beef juices. Pour in liquid (water, broth, or extra teriyaki sauce). Bring to a boil, reduce heat, cover, and simmer until rice is tender.

Add Vegetables: Add harder vegetables first (carrots, bell peppers), then softer ones (snap peas, mushrooms) a few minutes later.

Combine and Rest: Return seared beef to the pan. Cook briefly until heated through, then turn off heat and let rest, covered, for a few minutes.

Serve: Fluff rice with a fork and serve hot. Garnish with green onions if desired.