Thanks to all. We went to Total Beverage and wound up picking up a Dolcetto d'Alba based in part on the idea that the recipe supposedly comes from Bologna, so an Italian wine seemed in order. I'll comment back later about how it turns out.
Meanwhile, here's the recipe:
1/4 cup olive oil
2 Tbsp chopped fresh sage
2 cloves garlic
1 tsp kosher salt
1/2 tsp black pepper
1/4 tsp red pepper flakes
Zest of 1 lemon
1 boneless pork loin roast or pork shoulder roast (2-1/2 to 3 lb), trimmed of as much fat and silverskin as feasible
2 Tbsp unsalted butter
1/2 cup dry white wine
2 cups whole milk*
1 Tbsp cornstarch
1 Tbsp cold water
Salt and black pepper to taste
Purée oil, sage, garlic, kosher salt, black pepper, red pepper flakes, and zest in a food processor; coat pork with mixture.
Sear pork in butter in a sauté pan over medium heat until browned on all sides, about 5 minutes.
Deglaze pan with wine; cook until liquid is reduced by half.
Pour milk into a slow cooker; add pork and deglazing liquid. Cover; cook until pork is fork-tender, 4–5 hours on high heat or 6–7 hours on low heat. Remove pork and keep it warm.
Purée sauce until smooth**; transfer to a saucepan. Bring sauce to a boil. Dissolve cornstarch in water; add to sauce. Boil sauce 30 seconds; season with salt and pepper to taste.
Slice pork; serve with sauce. Garnish servings with sage sprigs, if desired.
*Be sure to use whole milk—2% milk or lesser kinds are too thin.
**They recommend using a handheld stick blender for this step. We don't have one, so I'm going to pour it into the regular blender. That might be awkward, so I may set the blender itself (not the base, of course) in the sink in case of a spill. Or I may pour it into the two-litre Pyrex measuring cup and then use that to put it in the blender. As I type it, I think that second method may be best.
