Scrub the sweet potato and grate with the largest side of a box grater. Place the shredded sweet potato into a colander over a large bowl. Peel and halve the red onion. Grate half with the box grater. Add the shredded onion to the sweet potato and toss everything with a pinch of salt. Thinly slice the remaining onion half.
Drain and rinse the cannellini beans. Zest the lemon. Add the cannellini beans to a food processor with half the lemon zest and ½ tsp salt. Begin to blend, while pouring in 2 tbsp olive oil and then 2 tbsp warm water. Blend the white bean purée until smooth.
Place the golden raisins in a medium bowl and cover with the champagne vinegar. Roughly chop the hazelnuts. Place a large skillet over medium heat and add the chopped hazelnuts. Toast, shaking the pan frequently, until lightly browned, about 4 to 6 minutes. Transfer the toasted hazelnuts to a plate to cool. Pick the parsley leaves.
Over the sink, squeeze the water out of the sweet potatoes and onions with your hands. Dry the large bowl and return the shredded vegetables. Add the Vegenaise, Greek seasoning blend, and a pinch of salt and pepper and mix well. Once the hazelnuts are cool, add them to the raisins along with the sliced onion, remaining lemon zest, aleppo pepper flakes, and a pinch of salt. Stir the agrodolce to combine.
Place a large nonstick skillet with 2 tbsp vegetable oil over medium-high heat. Form the potato mixture into 6 fritters. Use a spatula to transfer the fritters to the oil and press to flatten. Cook, reducing the heat to medium after 1 minute, until lightly browned and crisp, about 3 to 5 minutes per side. Transfer to a paper towel-lined plate and season with salt.
Return the skillet to high heat and add the green beans (half of the bag is for this recipe and half for the Charred Vegetable Succotash). Add 2 tbsp water and a pinch of salt and cook until crisp tender, 3 to 4 minutes. Stir the parsley into the agrodolce. Spread the white bean purée onto plates and top with sweet potato fritters. Drizzle with raisin hazelnut agrodolce and serve with green beans.