Steps
1. In a bowl, whisk together the eggs, soy sauce, and mirin until well combined.
2. Heat the vegetable oil in a non-stick skillet over medium heat.
3. Pour the egg mixture into the skillet and let it sit for a few seconds until it starts to set around the edges.
4. Gently stir with a spatula, folding the eggs from the edges towards the center.
5. Continue to cook and stir until the eggs are softly scrambled but still slightly runny.
6. Remove from heat and let the residual heat finish cooking the eggs.
7. Garnish with chopped green onions if desired and serve immediately.