For the jus, roast the beef bones really hot in a large pot.
As soon as the bones are slightly brown, add the root vegetables and roast everything until it is a nice dark brown.
Add the tomato paste and paprika powder, fry briefly and deglaze with some of the red wine.
Reduce and deglaze again. Then add water until everything is covered and slowly bring to a simmer.
Let the jus simmer for 4-6 hours, during which time you should keep adding water.
When the jus is ready, thicken with cornstarch and season to taste.