This is the luxurious variant of genmaicha. Roasted rice together with sencha becomes genmaicha. It is then topped with matcha, ie ground tea leaves. It is very intense flavors, with a good balance between greenery and the roasted.
We sometimes call genmaicha "Japanese bark bread". One can assume that it originally arose because rice was cheaper than tea. But it is a long time ago, and genmaicha has become a popular tea in its own right.
Our genmaicha matcha-iri comes from Uji outside Kyoto, the cradle of Japanese tea culture.
This tea is "thick", so you can drink it as it is, or as dessert tea.