In large pot, heat the olive oil over medium heat until hot.
Add the garlic and onion, and saute, stirring, 3 mins.
Add the tomatoes, cumin, ginger, salt and pepper, and cayenne.
Cook, stirring often, 5 mins.
Pour in the water and stir in the mung beans.
Bring to a boil, then reduce the heat to low, cover the pot, and let simmer for 30 mins.
Then, uncover the pot and let simmer an additional 15 mins, or until the mung beans are softened.
Turn off the heat and stir in the coconut milk.
Ladle into bowls and garnish each bowl with lime wedges and lots of cilantro.
