Fresh or frozen cranberries are very tart, but the amount of brown sugar can be adjusted to your taste.
Canned cranberry sauce can be substituted for the whole cranberries-use two 15 ounce cans. There are other ingredients in the canned sauce, so you should consider the amount of brown sugar you use. Maybe start with 1 cup, then add more after tasting, if desired.
Use a food processor to chop the onions, garlic and chipotle pepper. You want them as fine as you can get them.
This recipe was developed using about 1/4 ounce of chipotle pepper in adobo sauce-that was 1 pepper. To increase the heat, add more.
If you do not have an immersion blender, use a potato masher or large wooden spoon to smash the cranberries, or you can add them as is to a blender or a food processor.
If you do not have a food mill, a blender or food processor works very well. Make sure to process the sauce until smooth.
The final consistency of the sauce will depend upon the amount of beef stock or beef broth you add. You may use more than two cups of stock to get the consistency you like....that's OK!
To make this vegetarian, substitute olive oil or vegetable oil for the bacon grease and vegetable stock or broth for the beef stock.