Mix all of the Special Sauce ingredients in a small bowl and set aside. The sauce may be prepared ahead and refrigerated until needed. It will keep for about a week in the refrigerator. The recipe may easily be doubled for those who like plenty of sauce.
Peel the carrots, beets and onion, if using. I like to peel the stalk of the broccoli and cook that, too, but prefer to leave the peels on the potatoes. (Marga mentioned that, for the added nutrients, she also keeps the peels on the beets and carrots.) Cut the veggies into bite-size chunks or thick slices. Cut the kielbasa link into thirds or quarters.
In a large pot with a steamer insert (see notes) and about 2 inches of water, arrange the potatoes, carrots, beets, and onion like a color palette in the steamer basket. Set the kielbasa on top. Bring the water to a boil, cover the pot, and continue to cook on medium-high heat until the veggies are almost–but not quite–tender. The last time I prepared this, this step took 13 or 14 minutes. Remove the lid and carefully add the broccoli. Cook 5 minutes more or until the broccoli is crisp tender or cooked to your liking. Similarly, green beans should be added in the final 3-5 minutes, depending on thickness. Snaps peas require just a minute or two.
Remove the kielbasa and slice on the diagonal. Serve an assortment of vegetables on each plate along with the kielbasa slices. Drizzle some of the sauce over top or pass the sauce at the table. Optionally, place individual servings of sauce in small ramekins so everyone has his or her own portion for dipping. (In the latter case, you may wish to double the recipe.)