Aw, Isn't That Sweet?

No, it's not sweet at all. It's a bowl of potato-cauliflower soup. I don't have much of a sweet tooth anyway, but I can't resist some pretty colors in food.
Deep greens and browns and vivid reds and oranges are all possible in an antioxidant-rich diet, but with the hint of spring on the horizon, I was hankering for some healthful pastels.
Still, this is no wimpy soup. It's based on rich turkey stock, flavored with salt and sautéed onions, and kicked into heaven with a healthy swirl of crème fraîche, making it deeply wintery in taste, and rib-stickingly hearty in texture.
Oh, the color? It comes from purple cauliflower and purple potatoes.
OK, roughly:

1 purple cauliflower, broken into florets, stems discarded
4 purple potatoes
2 cups turkey stock (or your choice; chicken or veggie would work)
1/4 cup chopped onion, maybe even a little less
A little olive oil
Salt and pepper to taste (maybe the stock is already seasoned; taste it to see)
3 tablespoons crème fraîche (don't measure; just bloop some in)
A few drops of vinegar

Steam the cauliflower and potatoes, separately, until you can pierce them with a sharp knife. Set the potatoes aside to cool a bit, and shock the cauliflower in cold water to preserve color. The cooked cauliflower loses its precious lilac color and ends up more of a gray-blue-mauve. But once you've run it through the blender with half of the turkey stock, you can restore some of the lavender tone by judiciously adding drops of vinegar. Magic! (No, not magic. Science.)
Sauté the chopped onion in some oil until tender; if you are adding salt and pepper (taste the stock first), sprinkle it over the onions in the pan.
Put about half the stock with the onions and cauliflower into a blender. Purée to whichever level of smoothness turns you on.
When the potatoes are cool enough to handle, peel them by scraping with a dull knife. Cut them into chunks and add to the cauliflower purée in the blender with the remaining stock. Purée. (The cooked potatoes feel sticky when you cut into them, but they will not turn gluey in the blender; fortunately they possess a russet-like grainy texture.)
Now: How do you like the color? Too bluish? Add a couple of drops of vinegar and blend. Still need more pinkiness? A couple more drops; blend. Remember, you are altering the taste as well as the color, and you've still got some mildly tangy crème fraîche to swirl in.
Taste for salt and pepper. Swirl in the crème fraîche.
Reheat gently in a saucepan and serve.
Oh, wait! Garnish with an extra sploosh of crème fraîche and tiny cubes of cooked beet if you're feeling frisky.
Serves two very generously; would easily make four nice small starters. Or, it could be smeared on black velvet for a cool Jimi Hendrix painting.