Hot Italian sausage recipes from the north of Italy tend to include garlic, lots of garlic. You'll see that this recipe uses fennel instead of anise for the expected licorice flavoring, which is also typical in northern Italian cuisine.
I don't know that this recipe originated in Milan, but it is certainly made in the Milanese fashion.
I do know that it is a staple in my sausage making recipe collection. I like it best when I stuff it in 35mm hog casings, and I have even been known to run it through the meat smoker on occasion.
IMPORTANT
If you ever do decide to smoke this sausage, remember that it's important to add a level teaspoon of cure (Prague powder or Instacure) to the meat mixture before stuffing it.
This sausage should be cooled as soon as it is done. It can be kept in the refrigerator for 2-3 days or in the freezer for up to 3 months.
The addition of the garlic and coriander makes this an interesting and
tasty departure from the typical basic italian sausage recipe.
Here's a tip: Don't let sausage made with garlic spend too
long in the freezer as the garlic flavor tends to fade over time. Try
to use it up in the first 2 months.