Cut the thawed chicken breast into bite-sized pieces.
Heat a spoonful of olive oil in a pan, add the chicken breast, and when it starts to turn golden, add onion and sauté together.
Add the prepared sauce (3 soy sauce, 2.5-3 water, 1 allulose, 1 mirin), and simmer over medium-low heat.
Once simmered, beat one egg and pour it over, cover, and cook for 2-3 minutes.
Serve on top of rice.