https://www.simplyrecipes.com/microwave-oyakodon-japanese-chicken-and-egg-rice-bowl-recipe-7105509
Ingredients
1 1/2 pounds boneless skinless chicken thighs, cut into 1-inch pieces
1 small yellow onion, thinly sliced (about 2 cups) 
2 cloves garlic, minced
1/2 cup low-sodium soy sauce (see Recipe Note) 
3 tablespoons mirin
1 teaspoon sugar
1/2 teaspoon kosher salt, divided
1/4 teaspoon black pepper
4 large eggs
1/2 cup low-sodium chicken stock (see Recipe Note)
Cooked rice, for serving
Kimchi, for serving