Cut the tofu into 1" squares and let them dry. In a frying pan, heat up with 3 tsp of oil until white smoke appears. Add ginger roots, garlic, scallion, and fry until fragrant. Next, add in crumbled hamburger meat, bean paste, and tofu squares, mix well. After boiling, turn the heat down to med-heat, and cook for another 3 minutes. Pour in the corn starch mixture to thicken the sauce. Serve with scallions sprinkle on top.