Put the veal tripe in a pressure cooker with 10 2/5 cups (2.5 L) water. Boil about 30 min., then take the tripe out and cut it finely. Strain the broth.
In a bowl, beat 2 eggs, add the yoghurt and 4 tbsp flour to them. Stir well, then transfer the egg-yoghurt mixture to a suitable pot.
Add 2 ladles of the broth, 1 tsp black pepper, while stirring and place on the stove.
Stir nonstop until the mixture comes to a boil slightly and thickens. Add broth again and repeat this process several more times, while stirring nonstop, so it doesn't stick.
This whole process with boiling the egg-yoghurt thickener lasts about 20 min., then remove the pot from the stove. Make a roux with 7 tbsp oil and 1/2 tbsp paprika in a small casserole, add it. Press the garlic and add it to the soup. Upon serving, add chili if desired.