In a large saucepan or pot or Dutch oven over medium-high heat, heat the oil. Add onion, garlic and kielbasa. Cook, stirring occasionally, until the onions are soft, about 5 to 6 minutes. Stir in the potato/broth mixture and the remaining 1 cup diced potatoes. Heat to boiling, and then reduce heat to medium and simmer, uncovered, 10 minutes.