Vegetables. Most raw vegetables added to a healthy diet will tend to normalize cholesterol. This does not hold true if you alter the vegetable e.g. Fry the vegetables, which can make the cholesterol readings worse.
All. Nothing magic about any particular vegetable. No vegetable has cholesterol, an animal fat. There are high amounts of other sterols in oily vegetables like soybean, but it's more than just that. Vegetables have a wide spectrum of vitamins, fiber, hydration, and... If you're eating more vegetables, there is less room for meat, high fat, and high calorie foods. Eat your vegetables, mom was right!