Preheat oven to 350 degrees F.

Sprinkle pork with salt and pepper.

Heat oil in a braiser pan or dutch oven over medium-high heat until almost smoking.

Add the pork to the pan and sear to brown on all sides, about 2 to 3 minutes per side.

Remove pork from the pan and place on a plate.

Reduce heat to medium and add onion. Cook until onions have softened, about 3 minutes.

Return pork to the pan along with peach slices and wine. Cover and place in the oven.

Roast for 1 1/2 hours, or until pork has an internal temperature of at least 145 degrees F.

Place pork on a cutting board and let set for 15 minutes.

Put peaches, onions, and all pan juices in a blender. Blend until liquefied and pour sauce back into pan. Bring sauce to a simmer then reduce heat to low to keep warm until serving.

Slice pork and place on a serving platter. Serve with sauce.