In large skillet, heat 4 tablespoons olive oil over low heat. Add potatoes and onion, stirring to coat with oil. Add 1/2 cup water and salt; cover and cook, stirring occasionally, until potatoes are tender, about 15 minutes.
Meanwhile, make sauce in medium saucepan
over medium heat; heat 1 tablespoon olive oil. Add
garlic and saute 15 seconds. Stir in tomatoes, broth and saffron. Cover and bring to boil. Reduce heat and simmer 15 minutes.
In large bowl, beat eggs. Stir potato mixture into eggs. In 10-inch nonstick skillet, heat remaining 1 tablespoon olive oil over low heat. Add egg mixture and spread to an even layer. Cover and cook omelet until underside of eggs begins to brown and top begins to set, about 8 minutes.
Place baking sheet upside-down over skillet and invert omelet onto baking sheet. Slide omelet, topside-down back into skillet to brown on other side, about 3 minutes.
Transfer omelet to platter. Cut into wedges and serve with sauce.
Makes a great dish for brunches, lunches and