Place the tripe in a saucepan with the water. Let it boil uncovered, then skim off the foam. Put the lid on and cook for about 20 minutes, until the tripe is soft. Add salt and after 5 min remove from heat, pour off clear soup from tripe and collect. If necessary, fill up to 750 ml. Cut the tripe into thin strips.
In a saucepan, melt the fat, stir in the flour and cook a roux. Gradually stir in the cold tripe liquid. Simmer on very low heat for 5 min, pour in the tripe and simmer on low heat for another 5 min.
In the meantime, prepare the seasoning: Crush the garlic cloves with salt and mix with the vinegar. Prepare the garnish: Cut bread into small cubes, toast under a broiler or toast in butter. Keep warm.
Now mix the egg yolks with the juice of one lemon. Add some of the soup liquid, then pour it all together into the saucepan and stir heartily with a whisk. Season with salt.
Pour the boiling hot soup into a tureen. Melt the butter in a pan, pour in the paprika powder. After less than 1 minute, remove from heat and drizzle thinly on the surface of the soup. Bring to the table with the garlic-vinegar seasoning and toasted bread cubes.
Tripe must be precooked.