Melt the lard in a pan and sauté the garlic without turning it brown. Add the garlic to the water. Salt, pepper, simmer for 15 minutes. Then take it off the stove.
Now separate the eggs: add the egg white to the soup, stir. Mix the egg yolks with the vinegar.
Cut the baguette into slices, put a few slices on each plate, and spread the egg yolk mixture on top. Then add the soup and serve immediately.