Place the blackberry jam in a small saucepan over medium high heat.

Bring to a light boil, then lower heat and stir until it thins to a syrup.

Simmer about 10 minutes.

Remove from heat and cool fully.

In a bowl, mix the cooled jam, wine, balsamic vinegar, olive oil, mustard, garlic, soy sauce, orange peel and rosemary.

Taste and add 1 to 2 teaspoons more balsamic vinegar if you want to balance sweetness from the jam.

Season the pork with salt and pepper.

Place it in a zip top bag or glass dish.

Pour half of the marinade over the pork.

Seal or cover and refrigerate for 2 to 5 hours.

Store the remaining marinade in the refrigerator.

Set the sous vide bath to 140°F.

Remove the pork from the marinade and discard the used marinade.

Place the pork in a new sous vide bag with 3 to 4 tablespoons of the reserved marinade.

Seal and cook for 2 hours.

Remove the pork and pat dry.

Heat a grill or cast iron pan on high.

Sear the pork for 60 to 90 seconds per side.

Brush with a little reduced sauce during the sear if you want a sticky crust.

Rest the pork for 5 minutes.

Pour the reserved marinade into a small saucepan.

Bring to a boil, then reduce heat.

Simmer for 20 to 30 minutes until slightly thickened.

If using jam and the sauce tastes too sweet, add a small splash of wine or 1 teaspoon balsamic vinegar.

Slice the tenderloin.

Arrange on a platter.

Drizzle with sauce.

Add thin slices of orange peel on top.

Serve extra sauce on the side.