In a soup pot, saute the garlic and onions in the olive oil, stirring occasionally, until the onions are translucent. Add the potatoes and tomatoes. Stir in the thyme and water. Cover and bring to a boil, then reduce the heat to a simmer. Stem the green beans and cut them into 1inch pieces. Add the beans and sliced fennel bulb to the pot. Stir in the saffron, orange peel, and lemon juice. Simmer, covered, for 15 to 20 minutes, stirring occasionally, until the potatoes and green beans are tender. Add salt and pepper to taste.