Line a baking dish with foil. Place tenderloin on top of foil. Sprinkle evenly with salt, black pepper and allspice (I like to rub the allspice into the meat).
Cover the meat and cook at 400 degrees for 50-60 minutes.
Uncover and cook another 10-15 minutes so the meat will brown on top.
While the pork stands, melt 2 tablespoons butter in a small saucepan over medium-high heat.
Add shallots, and saute for 5 minutes or until tender.
Add wine and cook for 13 minutes or until liquid is reduced by half.
Reduce heat to low, whisk in preserves and remaining 2 tablespoons of butter.
Cook 2 minutes or until slightly thickened.
To serve, cut pork into 1/4 inch thick slices. Drizzle peach sauce over the meat.