Preheat your oven to 425°F (220°C). Place a sheet pan in the oven to preheat as well.
In a large bowl, toss the halved marble potatoes and broccoli florets with olive oil, salt, and pepper until well coated.
Carefully remove the hot sheet pan from the oven and spread the potatoes and broccoli in a single layer. Return the pan to the oven and roast for about 20-25 minutes, or until the potatoes are golden and crispy and the broccoli is tender.
While the vegetables are roasting, rinse the quinoa under cold water. In a saucepan, bring the vegetable broth or water to a boil. Add the rinsed quinoa, reduce the heat to low, cover, and simmer for about 15 minutes, or until the quinoa is cooked and the liquid is absorbed. Fluff the quinoa with a fork.
To make the vegan Caesar sauce, drain and rinse the soaked cashews. In a blender or food processor, combine the soaked cashews, lemon juice, nutritional yeast, Dijon mustard, minced garlic, water, salt, and pepper. Blend until smooth and creamy.
To serve, divide the cooked quinoa among plates or bowls. Top with the roasted marble potatoes and broccoli. Drizzle the vegan Caesar sauce over the vegetables. Enjoy!
Note: You can customize this recipe by adding other roasted vegetables or toppings of your choice. Feel free to adjust the seasonings and quantities to suit your taste preferences.