Place each chicken breast between two large pieces of plastic wrap. Using the flat side of a meat mallet or heavy skillet, pound each breast until it is uniformly about one-fourth-inch thick.
Season each.piece with one-fourth teaspoon salt and a pinch of pepper. Place each breast on top of a large piece of plastic wrap or wax paper.
In a large skillet, heat the butter and 1 tablespoons of the olive oil over medium-high heat until hot. Add the chicken, one piece at a time, and sauté until golden-brown, about 2 1/2 minutes on the first side and 30.seconds on the other. Remove the chicken to a plate. Set aside in a warm place.
Drain the excess fat from the pan and add the remaining tablespoons of oil over medium heat. Add the pancetta and sauté until browned, about 2 minutes. Add the shallot and sauté for 1 minute, until tender,then add the garlic and sauté just until aromatic, a few seconds, being careful not to brown. Add the wine, stirring to scrape up the browned bits at the bottom of the pan.
Stir in the chicken broth, the paprika, thyme and tomatoes. Allow the sauce to come to a simmer and cook for 5 minutes so that the flavors develop. Stir in the olives.
Add the chicken back to the pan, spooning the sauce over it. Cook for 1 minute, then remove the chicken to a plate. Spoon the sauce evenly over each piece, and serve immediately.