Preheat the oven to 350F. Line a baking sheet with parchment. Add seeds, oil, spices, and salt and toss to coat. Bake for 5-7 minutes, or just until fragrant. Transfer to a bowl or plate to cool. Increase oven to 450F or 425F convection..
Add the beets to the same baking sheet lined with parchment paper. Add olive oil and salt and toss to coat. Bake for 20-25 minutes, or until tender. Let cool for a few minutes.
In a high speed blender, add all of the dressing ingredients and blend until smooth.
Add beets and fennel to a large bowl along with about ½ of the dressing. Toss to coat.
Transfer to a platter (or your plate) and top with avocado, plenty of seeds, and herbs. Drizzle with a bit more remaining dressing.