First we had butter made from animal fats 
Then we had butter made from plants (some may call this ‘margarine’)
Now we have butter made from methane gas thanks to Bill Gates backed startup Savor

And if you are in San Francisco, you can try stuff made with Savor’s gas butter at Jane the Bakery https://www.fastcompany.com/91302926/this-butter-wasnt-made-from-plants-or-animals-it-was-made-with-methane

Of all the lifeforms to imitate, I definitely didn't think we'd be mimicking the nutritional intake of methanotrophic bacteria. Feels sus