Cut the tofu and zucchini into about 1-inch cubes. Cut the radish into thin small squares. Thinly slice the onion and pepper. Roughly chop the scallion. Slice the meat into thin strips.
Preheat a small pot with a little bit of oil. Sauté the meat, soybean paste, and chili pepper flakes, over medium heat for 3 to 4 minutes.
Add the water (or anchovy broth) and stir well to dissolve the soybean paste. Add the radish (if using a potato, add it in the next step). Boil over medium high heat for 3 to 4 minutes.
Add the onion, garlic, tofu, zucchini, and chili pepper. Boil for an additional 5 to 6 minutes. Throw in the scallion pieces and add the optional vinegar with a minute or two remaining.
Serve with a bowl of rice while it is still bubbling from the heat.
