Heat oven to 400 degrees F and line a large sheet pan lined with foil.
In a small bowl, mix curry powder, cumin, garlic powder, salt, pepper and cinnamon.
Rub chicken breasts in 1 Tablespoon coconut oil, lemon juice and 1/2 curry spice mixture and place in refrigerator.
In large mixing bowl, toss together onions, garlic, broccoli, carrots, mushrooms and 2 Tablespoons coconut oil and remaining spice mixture. Combine well and spread on baking sheet. Bake for 15 minutes.
After baking, move vegetables to edges of the pan to allow for chicken in the middle. Place chicken breasts on pan and pour any reserved marinade over top.
Bake for 20-25 minutes or until chicken is thoroughly cooked.