Add ground pork and crushed garlic to a mixing bowl. Sprinkle with salt, black pepper, paprika, oregano, basil, parsley, and red pepper flakes, if using.
Toast fennel seeds in a skillet over medium heat until fragrant (around 30 to 60 seconds). Crush with a mortar and pestle to release the flavor, then add to pork mixture.
Add wine/vinegar and gently mix the pork mixture with your hands just until combined. Don't over-mix or your Italian sausage will have a dense texture.
Cover with plastic wrap and refrigerate for a few hours or overnight to allow the flavors to develop. Cook as desired, crumbled, in sausage patties, or on pizza. Optionally, stuff into casings.
Notes
Lean sausage is a disappointment waiting to happen. Aim for about 20-30% fat for juicy, flavorful results.
Lightly toasting fennel seeds before grinding wakes up the oils and boosts the classic Italian sausage flavor.
If you can, refrigerate the sausage mixture for a few hours (or overnight). The seasoning settles in, and everything tastes more cohesive.
Cook a small test piece first and adjust seasoning if needed.
Store Italian sausage in the refrigerator, in an airtight container, for up to 3 days, or freeze in freezer bags for up to 3 months.