In a small bowl, stir together the rice, asparagus, scallions, soy sauce, oil, garlic, ginger, honey, and vinegar, and pour into a 12-oz. mug. Pack down.
Crack the egg over the top and sprinkle with salt. Cover and microwave until the egg is mostly cooked through, but if pricked still yields a molten yolk, 2½ to 3 minutes.
To eat, prick the yolk and let it bathe the rice and vegetables, serving as a sauce.