This recipe is adaptable to how much time you have.  I had roasted a whole bunch of garlic and had it in the fridge so I used roasted garlic and boiled beets.  You could also roast the beets and the garlic together until tender, probably about 1 hour, before proceeding with the recipe.  It'll be tasty no matter how you make it!

2 pounds beets, cooked and skins removed (either roasted or peeled, chopped and boiled)
4 (or more) garlic cloves, (preferably roasted, but raw is fine, too)
4 cups chicken or vegetable broth
salt and pepper
1/2 teaspoon dried thyme
1 tablespoon prepared horseradish
sour cream
fresh dill, minced (optional)

Puree a little bit of broth with the beets, garlic, salt, pepper, and thyme together until smooth.  Add more broth to get the right thickness and heat until hot.  Combine the horseradish with sour cream to taste.  Serve soup hot in bowls with dollops of the horseradish sour cream on top.  Garnish with the optional fresh dill.