In a stockpot or other large pot, heat the oil over medium heat. Add the onion and cook for about 5 minutes, until it is softened. Add the sausages and cook, stirring for about 1 minute, or just until the meat begins to brown. Add the potatoes, paprika, and salt, and stir well. Add the water, increase the heat and bring the contents to a boil. (Add a little more water, at least enough to cover the potatoes by 1-inch, if you prefer the stew more soupy.) Reduce the heat to medium-low, cover the pot, and simmer gently for about 30 minutes, until the potatoes are tender. Ladle the stew into shallow bowls and serve.