Preheat the oven to 450F or 425F convection. Line a baking sheet with parchment paper. Add sweet potatoes, oil and salt to the baking sheet and toss to coat. Bake for 10-15 minutes, or until cooked through and browned in spots. Remove from oven and toss with garlic powder and black pepper (if using). Set aside.
Add all dressing ingredients to a high speed blender, starting with just 2 tablespoons of water, and blend until smooth. If too thick, add more water, 1 tablespoon at a time, until drizzle-able..
Add lettuce, veggies, beans, corn, and sweet potatoes to a large bowl. Pour about 1 cup of the dressing all over. Top with cheese, tortilla chips, avocado and pickled red onion. Finish with a final drizzle of dressing and black pepper.