Boil sweet potatoes in enough water to cover them with a teaspoon of salt.Leave for 20 minutes or until they offer no resistance when pinched with a fork. Leave aside when ready.
In a small skillet heat the green sauce with green lentils. When ready to serve, make a small incision at the center of each sweet potato and stuff with two tablespoons of lentils in salsa verde.
Top with the diced avocado, drizzle a teaspoon of vegan sour cream and finish with minced cilantro, and scallions.