Lettuce

Red Mustard Greens: 1000 score

What could be more complicated that lettuce?   But if you are looking for a little be more nutrition consider what else might go on your burger or rough cut into your next mix of sauteed vegetables for a side dish.  Adding something nutritionally rich makes a difference in energy.  Bitter and strong greens that are often difficult for some to eat raw, ease their flavor when lightly cooked. Higher nutrient numbers offer more body energy. 
Take a look at these greens and their nutritional density index and see if you might want to add them to balance your own meals.  The Vegetable Alchemist.

Butter Lettuce: 585 score

Red Kale: 1000 score