Environmentally friendly low carb food

During my vacation we lived next door to a family that sold the most amazingly delicious eggs, from their hens that ran around in nature searching for their food (pictured above). After some rain the hens quickly ran out into the grass – I’m guessing some tasty worms appeared out of the ground when it got wet.
The yolk of these eggs had a fantastic yellow color. Probably you’d have to look for a long time to find healthier or more environmentally friendly food.
Seems to me these chickens have got to be a lot happier than the poor critters in those awful confinement structures.
BTW, Off-topic. Have you befriended with Staffan Lindeberg? Is he a vegeterian?
I have talked some with him. As far as I know he is not a vegetarian. I think he basically eats dairy free paleo food. With quite a few fruits. ;)