This recipe is found in Bruce Aidells's Complete Book of Pork by Bruce Aidells with Lisa Weiss (ISBN 0-06-050895-7). I've put my changes and amounts in brackets.
12 garlic cloves [9 cloves, 23 g]
4 tablespoons olive oil
1 pound cremini, portabello, or fresh porcini mushrooms [314 g cremini]
1 cup chopped onions [135 g]
Kosher salt
Freshly ground black pepper
2 1/2 pounds boston butt, cut into 3/4-inch-wide strips [1000 g total meat plus fat]
1/2 pound pork back fat, cut into 3/4-inch-wide strips
2 teaspoons chopped fresh sage [2 g]
1 teaspoon chopped fresh basil [0.5 g dried]
2 tablespoons chopped Italian flat-leaf parsley [4 g]
1 tablespoon kosher salt [19 g]
1 teaspoon freshly ground black pepper [4 g]
1. Put 8 of the garlic cloves and 1 1/2 tablespoons of the oil in a small microwaveable container, cover, and micrfowave on high for 2 minutes. Set aside to cool.
2. Preheat the oven to 400 F,
3. Slice the remaining 4 garlic cloves and toss them in a bowl with the whole mushrooms, the onions, the remaining 2 1/2 tablespoons oil, a sprinkling of salt, and freshly ground black pepper. Scrap the mushroom mixture and all the oil into a roasting pan and roast in the preheated oven for 5 minutes. Stir and roast for 5 minutes more until the mushrooms are soft and fragrant. Set aside to cool.
4. Using a meat grinder fitted with a 3/8 inch plate, grind the pork and roasted mushroom mixture into a bowl and refrigerate. Change to the 1/8 inch plate and grind the fat and the reserved cooked garlic and its oil. Combine the ground mixtures in a large bowl and add the remaining ingredients with 1 tablespoon kosher salt and 1 teaspoon pepper.
I found this to be a terrific sausage with a great mushroom flavor. It also had a good balance of garlic, herbs and salt. The mixture is slightly wet from the vegetables. I put it into sheep casings and also made 4 oz. patties for breakfast sandwiches.