Preparation
Place beans, water, rosemary, thyme, fennel seeds, and bay leaf in a 6-quart (or larger) pot or dutch oven (I love my 7-quart Lodge Enamel Dutch Oven). Bring to a boil and then simmer, with the lid cracked, stirring occasionally, for 1 hour.
Meanwhile, place garlic cloves in a small oven-proof dish, sprinkle with water, cover with foil, and roast at 350F for 30 minutes. Let cool; peel.
Add turnips, potatoes, onions, and carrots to bean mixture, return to a boil, and simmer, with the lid cracked, stirring occasionally, for 1 hour. (NOTE: After you add all the vegetables, you may think that the soup is going to be way too thick and that more water is definitely needed. It is not. It will be fine. Lots of liquid will cook out of the vegetables--plus what you want to end up with is a very thick soup). After simmering, remove bay leaf.
If using a traditional blender:
Carefully puree the roasted garlic and 2/3 of soup mixture in blender (in batches) on low speed until still slightly chunky. Return to pot of remaining soup.
If using a hand immersion blender (you know I love my KitchenAid Hand Blender):
Remove about 1/3 of the soup from the pot and place in a heat proof bowl. Break the roasted garlic cloves into pieces with your fingers and stir into the pot of remaining soup. Carefully puree soup and garlic until still slightly chunky. Stir unpureed bowl of soup back into the pot. (You can just blend up the entire pot of soup if you like, but I found it difficult to keep it partly chunky.)
Stir in parsley and simmer, with the lid cracked, stirring occasionally, for another 30 minutes, or until beans are completely tender. Salt & pepper to taste, garnish with fresh parsley if desired, and serve.
Other Ideas:
--By all means, use fresh rosemary and thyme if you have them (about 1 Tablespoon of each).
--A bowl of this soup, a nice green salad, and a loaf of warm, homemade bread (beer bread, perhaps?) make a well-rounded meal. If you are serving people who must have meat every time they eat, a plate of nice hearty sausages (such as bratwurst or kielbasa) could be grilled or pan-fried and served along with the soup. Or thickly slice the sausages on a diagonal and set several slices right on top of each bowl of soup.
--Make it a celebration of spring. For those fortunate enough to have access to the first vegetables of the season, you might consider making this recipe using half the beans and twice the number of vegetables--all baby versions. I haven't actually tried this, but I imagine that it would be absolutely splendid. You might only want to puree 1/3 of it, so that the chunks of individual vegetables remained more visible.