World traveler Andrew Zimmern calls this thick and hearty split pea soup "Grandma Zimmern’s Pot of Love," reminding us that no matter where our journeys take us, there's nothing quite like home cooking. Chef Zimmern likes to use a combo of three smoked sausages, but feel free to go full-on kielbasa to make this soul-satisfying meal in a bowl.
In a small skillet, toast the caraway seeds over medium heat, stirring until fragrant, about 2 minutes. Finely grind the seeds in a spice grinder. Set aside. Cut the Ukrainian sausage, kielbasa, and Krakowska into 4-inch pieces; remove and discard the casing of the Krakowska. In a Dutch oven or large pot, melt the butter. Add the sausage and cook over medium heat until browned all over, 10–15 minutes. While the sausages are browning, thinly slice the celery. Trim escarole, then thinly slice into ribbons. Cut off fennel fronds and reserve for garnish; remove outer layer of the fennel, then thinly slice the inner bulb. Peel and trim onion, then roughly chop into small chunks. Trim carrots, cut in half lengthwise, then slice into ⅛-inch half-moon shapes.
Remove browned sausages from pot and transfer to a plate to cool slightly, reserving the drippings. (Note: Refrigerate sausages if not using within 1 hour.) Meanwhile, over medium heat, sauté onions and fennel with a pinch of salt in the sausage drippings. Add ground caraway seeds and another pinch of salt while the onion/fennel mixture browns, 3-4 minutes. Bundle thyme sprigs with kitchen twine to make a bouquet garni, and add it to the pot. Add carrots and celery; stir, then sweat, 60–90 seconds. Add ham hock, escarole, yellow and green split peas. Stir to combine, then add chicken stock. Bring to a boil, then reduce heat to low and simmer until peas are tender, about 60–80 minutes.
Remove ham hock and set aside. Thinly slice the sausages; add them to the soup and simmer until the sausages are heated through, 8–10 minutes. Meanwhile, pull the meat off the ham hock, slice, add to the soup and simmer, 4–5 more minutes.
Remove bouquet garni and discard. Season the stew with salt, vinegar, and hot sauce. Garnish with reserved fennel fronds and freshly ground white peppercorns, and serve with baguette slices.