Thanksgiving Turkey Burgers - Martin's Famous Potato Rolls and Bread

Ingredients

• 1 small sweet potato (6 to 8 ounces)
• 1 tablespoon butter
• 1/3 cup finely chopped yellow onion (about 1/2 a small onion)
• 1/4 cup finely chopped celery (about 1 small stalk)
• 2 teaspoons finely chopped fresh sage leaves
• 1 teaspoon finely chopped fresh thyme leaves
• 1 teaspoon freshly minced garlic (about 1 medium clove)
• 1 pound ground turkey thighs or 85% lean pre-packaged ground turkey
• 1/3 pound loose pork breakfast or sage sausage
• Kosher salt and freshly ground black pepper
• 4 Martin's Sandwich Potato Rolls