Preheat your oven to 425 degrees F. Slice the top off of the head of garlic so that the cloves are exposed but the head is still intact. Place the garlic in the mold of a standard muffin tin. Drizzle the garlic with the olive oil and sprinkle with salt and black pepper. Cover with foil and place the pan in the oven. Roast the garlic for 40-45 minutes or until the garlic is fragrant and soft. Remove the garlic from heat and allow it to cool until it's cool enough to handle. Pressing the bottom of the garlic head, release the garlic from the head. Place the garlic in the bowl of your stand mixer.

While your garlic is roasting, prepare your carrots and sweet potatoes. Add the carrots and sweet potatoes to a large pot. Cover the veggies with just enough water so that it covers them. Season with salt. Place the pot over high heat and bring to a boil. Boil the veggies until they are tender, about 15 minutes. Drain, and transfer the veggies to the stand mixer with the garlic.

Also to the bowl, add the sour cream, butter and milk. Mix until the mixture is mashed to your liking. Season to taste with salt and black pepper. Enjoy the mashed sweet potatoes and carrots immediately or cover until you are ready to serve!