Rinse the mung bean sprouts and drain well.
Heat the cooking oil in a wok or frying pan.
Saute the shallots and tomatoes (sauteeing is always on medium-low heat) until softened.
Add the garlic and cilantro roots and stems, and continue sauteeing for another two to three minutes.
Add the chopped mushrooms. Sprinkle in a teaspoon of salt and a quarter teaspoon of pepper. Cook, stirring occasionally, for two to three minutes.
Add the green beans and julienned carrot. Continue cooking, stirring occasionally, for another two minutes.
Toss in the bean sprouts and cook just until the sprouts soften (do not overcook).
Taste, and add more salt and pepper, if needed.
Immediately transfer the cooked filling to a strainer set over a shallow plate to allow excess liquid to drip off.
Cool the filling to room temperature.