Gather the tools and ingredients for the recipe.

Preheat the oven to 350 °F (180 °C).

Carefully butterfly all the chicken breasts with a sharp knife.

Lay a slice of goat cheese along the length of the butterflied breast. Add ¼ of the chopped rosemary and close the chicken. Add a good pinch of salt and pepper. Repeat for all four breasts.

Heat a large, heavy-bottomed skillet over high heat.

Add the olive oil. When the oil shimmers, start to sauté all four chicken pieces. Cook on each side for about 2 minutes or until nicely golden brown. Remove from the pan and place on an aluminum foil-lined baking sheet. Bake for 20 minutes or until cooked through.

Add the mushrooms directly to the pan where the chicken was cooked, still over high heat. Add the salt and rosemary. Add the butter and garlic when the mushrooms have expelled most of their liquid (about 5-7 minutes). Reduce the heat to medium. Cook for 2 minutes, stirring frequently to prevent burning.

Add the Dijon mustard and cream to the sautéed mushrooms. Cook until thickened (approximately 2-3 minutes). Taste, season with salt, and set aside.

Once the chicken is cooked, remove it from the pan and spoon the mushrooms and creamy pan sauce over it. Garnish with rosemary leaves. Eat hot and enjoy!