Place green tea bag into boiling water and let sit for at least 10 minutes.
Place green tea into food processor or blender making sure to press down on the tea bag to get all of the tea out.
Place blackberries, oil, vinegar, onion, garlic, honey and salt on top of green tea in food processor or blender and blend until smooth, about 1-2 minutes.
Pour dressing through a fine mesh strainer while pressing down with a large wooden spoon to release any extra juices. **I've made this twice now. Once where I strained the dressing and left the pulp and another time where I poured the dressing into an airtight container with a lid and vigorously shook it before I used it. Both ways it came out great.
In a large bowl, pour shredded brussels sprouts mixture and chopped kale.
Top with walnuts, cheese and dressing. Serve immediately or refrigerate until ready to eat.