Soak the maitake and shiitake in separate bowls with warm water to cover for 10 minutes. Remove the mushrooms, squeeze out water and chop coarsely. Reserve 1 cup mushroom soaking water.
Heat the oil in a medium saucepan, and sauté the garlic and onions for 1 to 2 minutes. Add the maitake, shiitake, salt and pepper. Sauté for another 4 to 5 minutes. Add the rice, vegetable stock, garbanzo, mushroom soaking water, and tomatoes. Cover and bring to a boil. Reduce the flame to low and simmer for 1 hour. Remove from the flame and mix in the parsley. Serve.
4g fat (17% calories from fat),