Put each chicken breast between 2 pieces of plastic wrap and pound to 1/4-inch thickness, tapering thickness along the edges to 1/8-inch. Set aside until needed.
Combine the panko and garlic salt in a small bowl and drizzle with oil; toss until coated. Heat a large nonstick skillet over medium-high heat. When the skillet is hot add the panko and toast until light golden, stirring constantly. Pour the toasted panko into a shallow dish.
In another shallow dish, whisk together the egg whites, milk, cornstarch and mustard.
Line a jelly roll pan with foil (to catch any juices) then set a large wire rack over foil. Remove plastic wrap from chicken. Put the chicken on a work surface and sprinkle with salt and peppercorns; rub into the flesh. In a small bowl stir together the prosciutto, fontina, blue cheese and chopped basil. Divide the mixture into 6 portions. On each breast, put a portion of the mixture on the bottom half and toward the center. Roll the bottom edge of the breast over the filling then roll up tightly, tucking in the sides. Press firmly on the seam to secure. Roll the chicken in the egg white mixture to coat, then roll in the panko crumbs, pressing firmly. Arrange the chicken on the wire rack in the pan, spacing equally. Let rest for 20 minutes.
Preheat the oven to 350 degrees F.
For the chutney: In a heavy 1-quart saucepan add the butter and let it melt over medium-high heat. Add the onion and cook until tender, and stirring often, about 3 minutes. Stir in the vinegar, raisins, ginger, brown sugar, Worcestershire sauce, curry, salt, nutmeg and blueberries. Bring the mixture to a boil, then reduce the heat to low and simmer for 15 minutes, stirring occasionally. Remove from heat and slightly mash the blueberries with a potato masher. Cover the pan and set aside.
After resting the chicken for 20 minutes, put the pan in the preheated oven and bake until an instant-read thermometer reaches 160 degrees F when inserted into the center of the chicken roll, about 40 minutes. Remove from oven and let the chicken to rest for 5 minutes before serving. Transfer the chicken to a serving platter and serve topped with the chutney, (no need to reheat). Garnish with basil leaves and serve.
The chutney can be made ahead and is just as delicious cold or warm over the chicken.
A viewer or guest of the show, who may not be a professional cook, provided this recipe. It has not been tested for home use.