Heat the olive oil in a medium skillet over medium-low heat.
Add the garlic and shallot and cook until translucent, about 2 minutes.
Remove from the heat and let cool completely.
Combine the veal and pork fatback with the shallot mixture, red pepper flakes, fennel seeds, coriander, sugar and 1 tablespoon salt in a large bowl.
Transfer to a large plastic zip-top bag and refrigerate overnight.
At least 30 minutes before grinding the meat, place all of your tools (including the meat grinder parts, stand mixer bowl, stand mixer paddle attachment and sausage stuffer parts) in the freezer to chill.
Using your meat grinder, grind the marinated meat mixture twice through the small die plate into the chilled bowl of the stand mixer. Refrigerate at least 30 minutes, then return the mixture to the mixer and beat on medium speed using the chilled paddle attachment, 45 to 60 seconds. Refrigerate until ready to use.
Stuff the sausages (see Cook's Note)and, for best results, refrigerate overnight.
Before cooking, pierce each sausage several times with a pin. Grill over medium heat until the center registers 150 degrees F, 10 to 12 minutes. (You can also pan-fry or broil the sausages.)
Serve with cornichons, mustard and bread.
If you don't have time to stuff sausage links, cook the sausage mixture loose in a skillet or form it into patties for grilling or pan-frying.
