In a medium saucepan, bring 2 inches of water to a boil. In a steamer basket, add in the sweet potato, beet and beans, place basket over boiling water and cover. Steam for 12-15 minutes or until all ingredients are tender when pricked with a fork. Remove from heat and let cool slightly. Reserve steamer water.
Transfer all ingredients to a blender or food processor. Add in 1/4 cup liquid (steamer water, breast milk, formula, stock or water).
Puree all of the ingredient at high speed for 1-2 minutes or until you reach your desired consistency. Add in additional liquid in 1/4 cup increments if puree is too thick. I had to add in 1/2 cup of reserved steamer water to the puree pictured above.