Peel and slice beetroots, In a mixing bowl add 1 teaspoon of olive oil and pinch of salt , toss peeled and sliced beetroot with oil and salt mixture.
Line a baking sheet/tray with parchment paper and roast for 25-30 minutes , place the tray in middle rack.
Now add 1 tablespoon of olive oil and its butter into a thick bottomed pan , add sliced onion and basil , cook for 2-3 minutes on medium heat. Now add roasted beets and vegetable stock. You can make your vegetable stocks by boiling any leftover uncooked vegetables combined with garlic, bay leaf, whole red peppers for 15-20 minutes and then straining stock and discarding veggies and spices.
Cover the pan and let this simmer for 10-12 minutes.??Either wait for it to cool down so that you can puree it in food processor or you can use immersion blender to puree it. Finally add milk and either serve with drizzle of cream or if you are not a cream lover like me drizzle some more whole milk.