Break the rice apart in a large bowl to separate the grains; if using freshly cooked rice, let it sit in front of a fan for 10 minutes to evaporate excess moisture and prevent clumping.

Heat the oil in a large skillet or wok over high heat until it shimmers, then add the scallions, ginger, and garlic, stirring for about 1 minute until fragrant.

Stir in the carrot, bell pepper, salt, and a splash of water, then lower the heat to medium-high and cook for about 3 minutes until the vegetables are tender.

Increase the heat to high and add the shiitake mushrooms, leaving them untouched for 2 minutes to develop a golden-brown sear before tossing and browning the other side for another 2 minutes.

Add the rice to the pan and cook for 2 minutes, then pour in the teriyaki sauce and white pepper.

Lower the heat to medium-high and stir well for 2 to 3 minutes until the grains are evenly coated and the sauce has glazed the rice.

Stir in the dark soy sauce and adjust the seasoning with salt or more teriyaki sauce as needed, then serve hot, packed into bowls and inverted onto plates for a rounded shape.