Cook rice according to package directions, about 15 to 18 minutes for white rice. While still warm, fold in rice wine vinegar and sea salt with a fork. Cover and set aside.

While rice cooks, whisk together soy sauce, honey, ginger powder, and sesame seeds in a small bowl until honey fully dissolves. Set aside.

If salmon has skin, peel it away gently before cutting. Pat salmon pieces completely dry with paper towels. Sprinkle cornstarch over the salmon and toss gently until each piece is lightly coated. Shake off any excess.

Heat sesame oil in a large 13-inch skillet over medium-high heat until very hot and shimmering. Add salmon in a single layer without crowding. Cook undisturbed for 3 minutes to develop a golden crust, then flip and continue turning every couple of minutes until all sides are crispy and golden brown, about 8 to 10 minutes total. Cook in two batches if your skillet is smaller than 13 inches. Salmon should be opaque throughout.

Pour the prepared sauce into the skillet over the salmon. Toss gently to coat each piece. Cook together for 1 to 2 minutes until the sauce thickens and clings to the salmon. Watch closely as the honey can burn quickly at this stage.

Divide seasoned rice among four bowls. Top with glazed salmon, cubed avocado, sliced cucumbers, shredded carrot, and green onions. Add optional toppings like spicy mayo, torn nori, and extra sesame seeds. Serve immediately.