Preheat oven to 400F/200C. Using a fork, poke small holes in sweet potatoes going all the way round, about 1-inch apart. Line baking tray with parchment paper, and paint sweet potatoes with avocado oil to lightly coat. Bake for 40 minutes, or until cooked through.
In a bowl combine chopped red onion and garlic, cherry tomatoes, black beans, corn, and chopped cilantro. Add lime juice, olive oil, sea salt, pepper and cayenne pepper flakes. Mix to combine.
Prepare easy guacamole: Mash avocado in a bowl with lemon juice and a pinch of sea salt.
Prepare vegan sour cream: In a separate bowl mix together coconut yogurt, lime juice and sea salt.
Cut sweet potatoes in half and fill with black bean medley. Top with easy guacamole and drizzle with vegan sour cream.