Lay veal on flat surface. Place cheese on each piece, topped by a of slice prosciutto; sprinkle with salt and pepper. Roll up; secure with toothpicks. Heat olive oil in sauté pan. Dust veal rolls in flour. Place in pan, sauté on both sides until brown, about 2 minutes on each side. Remove from heat; drain off oil. Add 1/2 stick butter, another pinch of salt, another pinch pepper, sage and thyme. Deglaze pan with 1/2 cup white wine. Reduce by 3/4. Add mushrooms and 1/4 cup of the chicken stock. Reduce by half. Add 1/4 cup marinara and remaining chicken stock. Reduce until desired consistency. Place veal on platter; remove toothpicks. Finish plate with sauce and serve.