Rinse the beans. Line up several beans at a time and cut off the stem ends; cut into 2-inch lengths.
In a large heavy skillet or wok, heat the oil over medium-high heat. When hot, add the beans and bell pepper. Stir-fry 8 minutes. Reduce heat to medium after 5 minutes. Remove from the pan and set aside.
In the same skillet, add the ginger, pork, pepper flakes and soy sauce. Stir-fry, breaking up the pork with a spatula, and cook until the pork is cooked through. Remove most of the grease in the pan. Stir the sugar, black bean-garlic sauce and water into the pork, then put the beans back into the pan and cook, stirring often, 4-5 minutes, or until the beans are cooked. Taste a few of the beans. There should be no raw flavor, but crunchy, firm texture.
This main entree can be served with rice.