Instructions

1. Preheat the oven to 425 F (220 C). Line a baking sheet with parchment paper or a silicone mat and set it aside.
2. Dice the sweet potato into 1/2-inch (1 ¼ cm) cubes and divide the cauliflower into small florets. Arrange the vegetables on the prepared baking sheet. Drizzle the vegetables with olive oil and sprinkle with salt. 
3. Place the baking sheet in the oven and bake for 20 to 25 minutes, stirring halfway through the baking time.
4. Meanwhile, to make the avocado mayo, add the avocado, lemon juice, apple cider vinegar, onion powder, garlic powder, and salt to a blender and blend until smooth. Add the water, 1 Tablespoon (15 ml) at a time, and blend until desired consistency is achieved. For a creamier texture, add the olive oil and blend until smooth.
5. To assemble the bowls, divide the roasted vegetables evenly between two bowls. Arrange the roasted vegetables with the tuna, shredded cabbage and arugula. Add a dollop of avocado mayo to each bowl and serve.