Preheat the oven to 450° and position racks in the upper and middle thirds. In a very large bowl, toss the butternut squash with the brussels sprouts, onion wedges and 1/2 cup of the canola oil; season with salt and pepper. Spread the vegetables on 2 large, sturdy rimmed baking sheets.
In the same bowl, combine the cup of yogurt with the ginger, garlic, curry powder and the remaining 1/2 cup of oil and season with salt and pepper. Add the chicken and toss until thoroughly coated. Arrange the chicken on top of the vegetables. Roast for about 40 minutes, rotating the pans halfway through, until the vegetables are nearly tender and the chicken is nearly cooked through. Pour off any accumulated liquid in the pans and roast for about 20 minutes longer, until the vegetables are tender and the chicken is lightly browned. Transfer the chicken and vegetables to a platter and serve with warm naan and yogurt.