What's the secret?  Chef Missy fills us in

In a medium pot, cover carrots and potatoes with cold water and boil for about 20 minutes until yams, and especially carrots, are very tender. If the carrots aren’t thoroughly cooked, they’ll leave telltale little nuggets of vegetables, which will reveal their presence (a gigantic no-no for the sneaky chef).

Drain the potatoes and carrots and put them in the food processor with two tablespoons of water. Keep on high until the orange puree is smooth; no pieces of carrots or potatoes should remain. Stop occasionally to push the contents from the top to the bottom.

If necessary, use the third tablespoon of water to make a smoother puree, but the less water the better.This makes about 2 cups of orange puree.

Double the recipe if you want to store another cup of puree. Store in refrigerator up to three days, or freeze 1/4 cup portions in sealed plastic bags or small plastic containers.