Set the Sous Vide Precision Cooker to 140ºF (60ºC).

Butterfly each chicken breast. Season with salt and pepper.

Wrap 2 pieces of ham around each piece of cheese. Place ham-wrapped cheese in the center of each chicken breast. Fold the chicken breasts around the ham.

Place the stuffed chicken breasts in a large zipper lock or vacuum seal bag. Seal the bag using the water immersion technique or a vacuum sealer on the dry setting. Place in the water bath and set the timer for 1 1/2 hours.

While chicken is cooking, prepare the sauce. In a medium sauce pan, melt butter over medium heat. Stir in flour until mixture clumps together. Gradually whisk in milk, working out the lumps as you stir. Add dijon mustard, garlic powder, parmesan cheese, and salt and pepper to taste.

About 15 before the chicken is finished, begin heating the oil for frying: Pour about 2 inches of oil into a large Dutch oven. Heat the oil to 375ºF over medium-high heat.

Place the flour, heavy cream, and panko each in their own shallow bowl. Season the flour with salt and pepper.

When the timer goes off, remove the bag from the water bath. Remove the stuffed chicken breasts from the bag and pat very dry with paper towels.

Dust the chicken with the flour and then dip it into the heavy cream. Place the chicken to the panko and roll to coat.

Carefully transfer the chicken to the hot oil and fry until golden brown, 2 to 3 minutes.

Let drain on a paper towel-lined plate for 1 minute and serve, garnished with parsley.