Bring 1½ cups (375ml) water to a boil.
Add the rice, stir and return to the boil.
Reduce to a simmer, cook for about 15 minutes until rice becomes tender.
Remove from heat, and allow to steam for about 5 minutes.
Meanwhile, make a sauce by tossing and whisking together the vinegar, sesame oil, soy sauce, and cornstarch in a small bowl, and then set aside.
In a large non-stick frying pan, set heat to medium-high and heat up vegetable oil. Toss in bell pepper, carrots, ginger, and scallion whites.
Stir occasionally, cooking for about 5 minutes until the carrots are tender.
Toss in the scallops and scallion greens.
Allow to cook for 3 minutes, stirring occasionally, until the scallops are done.
Stir the sauce briefly, and add to the frying pan.
Cook for 1 minute until thickened.
Serve the scallop stir-fry over the hot rice.