Peel, and chop the sweet potatoes. Toss with cumin, paprika, garlic and olive oil. Season with salt and pepper. Bake for 30-35 minutes on a lined baking sheet. Remove from the oven, and let cool for 5 minutes.
Add sweet potatoes, diced red onion, chickpeas, and vegan Worcestershire to the food processor. Pulse until combined.
Scoop mixture into a large bowl, add cashews and rolled oats.
Form into patties.
In a large sauté pan, cook burgers in coconut oil over medium heat for 5-6 minutes per side, or until lightly browned. Sauté the onion sliced for garnish before turning off the heat.
Peel the avocados and cut in half for serving.
Layer the aioli, patty, sautéed onions, arugula on one half of the avocado and top with the other half.
For the aioli, mix all ingredients in a small bowl and stir with a fork until well incorporated.