Wash the legume mix in cold water, drain and then soak in twice as much cold water for 1 hour.
Wash the tomatoes, scrape out the stones and dice the firm pulp. Peel the carrot, dice it into small pieces. Peel and dice the onion. Clean the celery as if you dice a carrot. Squeeze the salsiccia meat out of the intestine and form small balls approx. 3 cm in diameter. If not dried, chop the oregano into small pieces. Grate the Parmesan. The bacon rind mentioned above is not mandatory, I only had it from freshly smoked food and didn't want to dispose of it. But it gives the soup a good taste.
When the legumes are swollen, put them in a larger saucepan with the soaking water. Actually, you should pour it off and prepare the legumes with 300 ml of vegetable stock, but I decided on the "own variant", first added only 300 ml of stock, seasoned everything with salt and pepper, added the rinds of bacon and cooked it brought. At the beginning it starts to foam quite a bit. You can skim off this foam with a fine sieve and let the soup simmer with the lid slightly tilted and at medium heat. The packaging instructions for the finished legume mix stipulated a cooking time of 40 minutes. But that was way too long, and thank God I tried it after 20 minutes and noticed that they were almost done. The lentils and broad beans cook slightly, but they give the soup a natural texture. With the remaining 200 ml of broth you can make the soup more liquid - if you wish - or store it if there is a leftover to make it a little more liquid again, as it swells after cooling and becomes quite compact.
While the legumes are cooking, heat the 3 tablespoons of olive oil in a pan, fry the carrots, onions and celery in it, sprinkle with oregano, turn the heat down, let it simmer for about 3 minutes, turning several times and after the 20 minutes above Add the cooking time of the legumes, fold in well and simmer for another 5 minutes. Then turn off the heat, add the tomato pieces and salsiccia balls and let them simmer in the hot soup for another 5 minutes.
Before serving, drizzle about 1 - 2 tablespoons of olive oil (per serving) on the surface and sprinkle with some Parmesan.