Heat oil in heavy large saucepan over medium-high heat. Add onion; sauté until tender, about 5 minutes. Add next 4 ingredients; stir 1 minute. Add zucchini and tomatoes with juices; bring to boil. Reduce heat and simmer until zucchini is tender, stirring occasionally, about 10 minutes. Add garbanzos and olives; simmer 3 minutes.
Preheat oven to 300°F. Mix first 3 ingredients in bowl. Season with salt and pepper. Working in batches, spray large nonstick skillet with nonstick spray; add 1 teaspoon oil. Heat over medium-high heat. Add potato mixture by 1/3 cupfuls, spreading each to 3-inch round. Cook until pancakes are brown, about 5 minutes per side. Transfer to baking sheet; keep warm in oven.
Place 3 pancakes on each of 4 plates. Spoon stew over and serve.