COARSELY CHOP THE BACON, place in a food processor and process until smooth. Add the ground turkey and sage and process just until well mixed. Scrape into a bowl and form the mixture into 4 patties. Place in the refrigerator, covered to chill for 20 minutes. Heat the butter in a medium skillet over medium heat. Add the patties and cook 4 minutes. Turn, add the mushrooms and continue to cook 5 to 7 minutes more. Remove the patties from the heat and place on hamburger buns. Garnish with some saut�ed mushrooms.