Fill Masterbuilt fryer to the MAX fill line with water. Set to 375°F and bring to a boil; this will take approximately 15 to 20 minutes. Although cooking time on this recipe is short, water may need to be added if steamer is used for more than 60 minutes.
In the steamer basket, layer sliced red potatoes first, then carrots, broccoli, and cauliflower then squash, and finally the onion. Lightly sprinkle each layer with sea salt and pepper.
Cover and steam at 375°F, until the potatoes are done and the carrots are tender but still crisp, approximately 6 to 8 minutes. Note: Do not lower basket into water when steaming.
Remove vegetables from steamer and place into a large serving bowl; toss with the extra virgin olive oil to coat, and serve warm.