Gourmet Express: How to keep vegetable green?

Green vegetables contain chlorophyll, when chlorophyll is cooked, it produces carbon dioxide. Since you have to cover the vegetables to steam them, the chlorophyll turns a drab, grayish color. You can prevent this by boiling the greens, in salted water. Use a large amount of water, then add salt.

Gourmet Express: How to keep vegetable green? Source: Supplied: Mrs Lee