Curried-Chicken and Vegetable Pan Roast

butternut squash in 1-inch cubes (from one 2 1/2-pound squash)

brussels sprouts, halved

large red onions, cut into thin wedges

canola oil

Salt and freshly ground pepper

plain fat-free Greek yogurt, plus more for serving

minced fresh ginger

large garlic cloves, minced

Madras curry powder

skinless, boneless chicken thighs

Warm naan, for serving