First you need to brew tea.
I chose black tea with cornflower petals and barberry berries.
Pour boiling water over the tea and insist until it cools down completely.
Squeeze the juice out of half an orange, cut the other half into rings.
Put slices of orange in a jug, strain the cooled brewed tea there, add orange juice and pour in kvass.
If desired, add sugar and ice.
I added sugar, and it seemed so delicious!