Drain and rinse the beans. Set aside.
In a large bowl, combine the eggs, milk, a pinch of salt, and pepper. Whisk until smooth.
Melt butter in a large skillet over medium-low heat. Pour the whisked eggs into the skillet and gently fold them with the spatula as they begin to set. Avoid over-stirring the eggs.
When the eggs are nearly set, gently fold the beans and chiles into the scrambled eggs. Drizzle taco sauce over the eggs, then top with pepper jack.
Place a lid on the skillet and let it warm for about 5 more minutes, or until the eggs are fully set and the cheese on top is melted.
Top the eggs with the diced tomato and green onion just before serving.