Cashew cream: soak the cashews in a bowl of water for at least 2 hours (or up to 8 hours). Rinse and discard the water.
Add the cashews to a blender jar with lemon juice, apple cider vinegar and salt. Blend to a smooth paste thinning with water as required. Taste and adjust seasoning. Refrigerate until required.
Preheat the oven to 180 C.
Quarter each beet and wrap them all together in one piece of foil. Add the pumpkin to a baking tray and toss with olive oil, salt and pepper. Roast the beets and pumpkin together for 45-50 mins.
Check the beets. If a knife inserted doesn't go through without resistance they might need a bit longer. You want them soft and yielding.
Chop the beets into bite-sized pieces. Add to your serving plate along with the pumpkin. Dollop over the cashew sour cream just before serving. I like to sprinkle some pepper over the top. Serve warm or at room temperature.