Trim off and discard any thick layers of fat from the pork, then cut into approx. 1" chunks. Trim any thick layers of internal fat as you go (you don't want to remove all the fat, just any especially thick layers).
Heat 2 tablespoons oil in a soup pot or Dutch oven over medium-high heat.
Add half of the pork in a single layer and sprinkle with about ¼ teaspoon each of salt and pepper. Let the pork cook without moving the pieces for at least 5 minutes, or until they develop a nice brown crust on one side.
Using cooking tongs or a spatula, stir the pork around to brown the other side of the pieces, about another 5 minutes. Sprinkle this side with another ¼ teaspoon of salt as well.
Use a slotted spoon to remove the pork to a dinner plate. Repeat the process with the remaining pork, adding more oil to the pan if it starts to look dry.
While the pork is cooking, peel and dice the onion. Peel and thickly slice the carrots into coins. Thickly slice the celery. Peel and mince the garlic cloves.
After you remove the second batch of pork from the pot, there should be about 2 tablespoons of oil in the pain. If there's less, add more oil. If there's more, don't worry about it.
Add the onions, carrots, celery and garlic, plus about ¼ teaspoon each of salt and pepper. Saute, stirring occasionally, until the onion is soft and transparent, about 8-10 minutes.
Add the tomato paste and saute, stirring occasionally, until the paste has darkened in color, about 2-3 minutes.
Add 1-2 cups of the broth (just eyeball it, no need to measure) and use a spatula to scrape up any brown bits on the bottom of the pan. Add the rest of the broth, the caraway seeds and the pork, plus any accumulated juices on the dinner plate.
Turn the heat up to high to bring the broth to a boil, the reduce the heat to medium low and let it simmer steadily for 45 minutes.
Meanwhile, halve the cabbage through the core and cut out and discard the core. Thinly slice the cabbage, then cut the slices crosswise into approx. 1" pieces.
After the pork has been simmering for 45 minutes, stir in the cabbage. You should be able to get everything just barely submerged in the broth, but if not, add water or more broth until you can.
Let the stew simmer for another 15 minutes. Stir in the herbs, if using. If you want it soup-ier, add more water or chicken broth. Taste and adjust seasoning then ladle up!