Sauté the onions over low heat, then add the beef. Let it brown, then deglaze with the wine. Add 3/4 cup water (about 200 ml) and cook over low heat for 3 hours.

Let it cool, then remove the meat from the bones and cut it into small pieces. Use an immersion blender to puree the onions, then add the meat back in and cook for another hour.

Let it cool again and refrigerate the pot. Once the fat rises to the top, remove it with a spoon. Return to the stove and simmer until it reaches your desired thickness.

This sauce is perfect for serving with square spaghetti alla chitarra (https://cookpad.wasmer.app/it/r/15532296) or canederli (https://cookpad.wasmer.app/it/r/15960600).