Heat 1 tablespoon of the oil over medium heat in a large skillet. Add the bean sprouts, bell peppers, yellow onion, and carrots. Cook until the vegetables are softened.
In a large bowl, whisk the eggs and soy sauce together. Add the softened vegetables and half of the green onions. Stir to combine.
In the same skillet, add 1 more tablespoon of oil if needed to coat the pan. Pour 1/4 of the egg mixture into the skillet, forming a pancake shape. Cook for 3-4 minutes on each side until golden brown and cooked through.
In a small saucepan, whisk together vegetable broth and cornstarch dissolved in 2 tablespoons of water. Bring to a simmer over medium heat, stirring constantly until the sauce thickens.