Heat oil in a medium saucepan over medium-high heat.
Add onion; saut 10 minutes.
Add garlic, and saut 1 minute.
Add tomato, and cook 5 minutes, stirring frequently.
Add potato, bell peppers, salt, black pepper, and broth; bring to a boil. Cover, reduce heat, and simmer 20 minutes or until potato is tender, stirring occasionally.