Preheat the oven to 200°C (400°F), with the fan setting. Or increase slightly if using the top and bottom heat.
Prepare all the vegetables. Cut the cauliflower and broccoli into bite-sized florets, peel and cube the sweet potato, turnip, and parsnip, slice the onion, and halve or quarter the mushrooms if large.
Arrange all the vegetables on a large sheet pan. Drizzle with avocado oil and sprinkle with the nutritional yeast, thyme, oregano, garlic powder, salt, and pepper.
Toss well to ensure all the vegetables are evenly coated with the oil and seasonings. Spread them into an even layer.
Roast for 30 to 35 minutes, stirring once or twice during baking, until the vegetables are tender and lightly caramelized around the edges.
Remove from the oven and serve warm. Drizzle with extra virgin olive oil and finish with a squeeze of fresh lemon juice and Tabasco sauce.
