Preheat the oven to 375°F. Lay the 2 thin chicken breasts flat. Spread each with 2 tablespoons Boursin and top each with 1 slice prosciutto. Roll tightly and secure with toothpicks or twine.
Heat 1/2 tablespoon olive oil and 1/2 tablespoon butter in an oven-safe skillet over medium-high heat. Sear the rolls for 2 to 3 minutes per side until browned.
Add 1/4 cup white wine or chicken broth and scrape up the browned bits for about 1 minute. Transfer the skillet to the oven and bake about 12 to 15 minutes, until the chicken reaches 165°F.
Move the chicken to a plate. For the optional sauce, return the skillet to medium heat and stir in 1/2 teaspoon Dijon, 1/4 teaspoon garlic powder, and 1/4 cup heavy cream. Simmer 2 minutes until lightly thickened.
Remove the toothpicks or twine, spoon the pan sauce over the chicken, and serve.