Combine the brussel sprouts, carrots, chicken, olive oil, curry powder, garlic powder, salt and pepper in a large bowl and toss to evenly coat. Spread into an even layer on a large baking sheet. Bake for 15 minutes, stir, and bake for an additional 10 to 15 minutes, until nicely roasted.
For the Parsnips:
Meanwhile bring a large pot of water to a boil and add the parsnips. Boil until the parsnips are very tender. Drain and return to pot (turn off heat). Add 3 tbsp of cream, butter, sour cream and garlic powder. Use a potato masher to mash until desired consistency, adding more cream if needed. Season with salt and pepper and keep warm.
For the Sauce:
To make the creamy curry sauce, simply melt 3 tbsp of butter in a small sauce pan over medium low heat and whisk in the curry powder until smooth. Gradually whisk in the remaining ingredients until smooth and let simmer over low heat, whisking occasionally, for 10 minutes. *Stir in the garam masala just before serving if desired.
Place a cup of parsnip mash on your plate, topped with a helping of the curry chicken and brussel sprouts, then drizzle with the creamy curry sauce. Enjoy!