Roasted Veggies: Place the rack in the center of the oven. Preheat oven to 400°F.
In an ovenproof skillet, brown rutabaga and potatoes in butter. Add onion and stir well. Add salt and pepper. Cook in oven about 40 minutes or until veggies are tender. Stir the veggies a few times during cooking.
Sausages: Prick the sausages with a fork and put in a saucepan with water. Bring to boil and let simmer slowly about 5 minutes. Drain.
In a skillet, brown the sausages in oil.
Spicy Honey Mustard: Meanwhile, in a bowl, mix all the ingredients. Serve the sausages with roasted veggies, spicy honey mustard and sour cream.