Slice the bacon into strips.
Heat a large skillet over medium-high heat. Add the olive oil and the bacon and cook until golden and crispy.
Score the top of the chicken breasts by slicing crosswise with a sharp knife about ¼ inch (6mm) into the flesh, every half inch all down the breast. Season with salt and pepper to taste.
Place the chicken into the pan seasoned side down and cook until golden brown, about 5 minutes. Flip chicken to brown on the other side.
Slice the shallots and add to the pan along with the rosemary and thyme.
Spoon in the Dijon mustard before scattering in the California Prunes whole.
Carefully add the brandy, and simmer for a couple of minutes to boil off the alcohol. Alternatively, you can carefully light the brandy with a long match after you add it to the pan. If you are lighting the brandy, be careful and stand back as it burns, then use a pan lid to put it out.
Pour in the heavy whipping cream and stir together to form a smooth, creamy sauce.
Simmer for 5 minutes longer, or until the chicken is cooked through. The internal temperature of the chicken breasts should be 165°F (75C) on an instant-read meat thermometer. Season with a few dashes of Worcestershire sauce. Garnish with fresh tarragon.