Often on T"u BiSh'vat people like to eat members of the shiv'as haminim - the Seven Species by which the Land of Israel is praised. Some of them, such as grapes and dates, are easy enough to come across in their unadulterated forms. But when it comes to wheat and barley, people often resort to cooked or baked grain derivatives rather than consuming the fruit in its pure form. Where (preferably in the U.S.) can an average consumer easily get hold of grains of wheat and barley straight from the stalk?
You can buy plain pearled barley in the grocery store, usually near the dry beans. Many people use it for cholent. You can certainly cook that up plain as a starchy side dish, and you might be able to roast it. Are you hoping to eat it raw?