Pan roast the monggo beans until brown. Set aside to cool. Lightly crush the monggo beans until it splits open.
Combine roasted monggo beans and water. Boil and simmer until tender, roughly 40 minutes. Drain excess water and mashed the boiled monggo beans until mushy. Set aside.
Saute ginger, garlic, onion and tomatoes in olive oil. When tomatoes are tender, mashed everything with the back of your wooden spoon.
Add water and bouillon cubes and let it simmer for 20 minutes.
Add the vegetables and season with fish sauce and black pepper.