Cook the cinghiale in a medium heavy-bottomed saucepan over medium heat until browned rendering the fat.
Drain the excess grease from the pot.
Then, add onions, rosemary and garlic and cook, stirring, until translucent and softened.
The liquid from the onions and garlic should be enough to scrap up the brown bit from the bottom of the pot.
Stir in remaining ingredients and reduce heat to low.
Simmer uncovered, stirring occasionally, until reduced and thickened to a jam-like consistency, about 1 hour.
Once the right consistency is achieved discard bay leaf.
Transfer to a blender and pulse to combine, leaving some chunks.
Use immediately, or store in the refrigerator for up to 3 days.
This recipe also freezes well in an airtight container.