Preheat oven to 400°F (204°C)
Scrub the sweet potato clean, pat dry, pierce it with a fork or paring knife several times, and brush a light layer of olive oil on the skin (optional). Cut the potato in half and lay the flat side down on a baking sheet (use parchment paper for easy clean up. Roast for approximately 1 hour, or until the potato is fork tender and the edges are caramelized.
While the potato is roasting, heat 1 tablespoon of olive oil in a skillet on medium-high heat. When the oil is hot, add the diced onion and sauté for approximately 5 minutes, or until the onion softens and becomes translucent.
Add the minced garlic and 1 teaspoon of Italian seasoning to the pan with the onion and stir to combine. Cook for another 2 minutes, stirring often.
Brush the remaining 2 tablespoon of olive oil on the rounds of the bread and grind or sprinkle a thin layer of sea salt over the bread. Toast in the 400°F (204°C) oven for approximately 5-10 minutes, or until the bread is lightly golden brown.
When the potato is cool enough to handle, remove the skin and place the potato in a medium bowl.
Add the ½ teaspoon of truffle oil, onion mixture, and salt and pepper to taste. Stir until the onion mixture is evenly combined with the potato.
Spread the sweet potato mixture on the toast and top with a dollop of vegan ricotta and minced parsley.
Refrigerate the sweet potato mixture for up to 3 days.
Best when eaten the same day that you make it.