Place potatoes in a large saucepan over medium heat, and cover with water. Bring to a boil, and cook until tender. Drain, and set aside.
Heat oil in a large, heavy skillet over medium heat. Saute the onion and garlic with the basil, rosemary, and oregano until the onion is just tender. Throw in the potatoes, and fry until lightly browned. Cover with spinach, and sprinkle with vinegar. Cover, and cook on low until the spinach is tender.
Remove from heat, and stir the mixture together. Season with salt and pepper.