Interesting recipe! I've never heard of a few of these foods (chickweed, triticale) but am looking forward to trying it out.
You can easily substitute wheat berries or rye berries or even brown rice for the triticale. It will change the nutritional profile, but the taste will be similar.
Chickweed is all over the Internet these days. It's a great foraged green that has lots of vitamins. It can be made into soups, salads, and a chimichurri.