Less appetizingly, but probably more nutritiously, most green leafy vegetables can be blended with water or milk and consumed in milkshake form. I'll often take three or four cups (that's a lot) of spinach and blend it with two cups whole milk and chocolate protein powder. This actually tastes good, if not delicious; a portion half that size is probably a solid amount of food for most people. Even without the protein powder or other flavoring, it is drinkable. Lower portions of vegetables give you better taste for less nutrition. Not a great culinary feat, but a very efficient way to improve diet quality, and eating vegetables raw is probably more nutritious than boiling them extensively.