Cut tofu into 1 1/2-inch square pieces, then cut each piece into 2 triangles. Pat dry.
Heat oil in a wok or large skillet. Fry tofu until golden brown. Remove tofu from pan and remove oil, leaving only 2 tablespoons. Add ground pork to skillet; fry until pink is gone. Add bean paste, garlic and ginger. Add soup stock, then add browned tofu. Cover and cook over low heat for 2 minutes.
Add salt and sugar; bring to a low boil. Make a paste of cornstarch and water; add to mixture and stir until thickened.
Serve garnished with green onions.
Serves 4 to 6