Trim the tops and stems off the beets and set aside.
Peel the beets and potato and cut them into bite size pieces.
Place the vegetables in a roasting pan lined with parchment paper and roast in the oven for 20 to 25 minutes, until fork tender but still a bit on the firm side.
Make sure you keep your veggies separated so the beets don't end up staining the potatoes.
While this is happening, rinse and dry the beets tops and stems and chop them coarsely. Place them in an airtight container and refrigerate until you are ready to put the salad together.
When the veggies are nice and roasted, take them out of the oven and let them cool for a while then transfer them to separate containers and place them in the fridge to cool completely, ideally overnight.
The day of
Add all the ingredients for the vinaigrette to your small blender or food processor and process until smooth and well incorporated. Set aside.
Divide the greens between two serving plates and top with beets, potatoes, sliced avocado and pumpkin seeds.