Grilled Stuffed Mushrooms with Turkey-Sage Filling

Recipe courtesy of Isabelle from Crumb: A Food Blog.
Prep Time: 15 mins. | Cook Time: 20 mins. | Serves: 4 as a main, 8 as an appetizer
Ingredients
1 tbsp olive oil
2 shallots, finely minced
1 clove garlic
1 lb lean ground turkey
1 egg, lightly beaten
1/4 cup finely chopped walnuts
1/4 cup panko breadcrumbs
1 tsp Worcestershire sauce
1 tsp finely chopped fresh sage
1 tsp finely chopped fresh parsley
1/2 tsp salt
1/2 tsp fresh ground pepper
16 large button mushrooms
1/2 cup finely shredded asiago cheese
Method
1. In a large sauté pan set over medium-high heat, cook the shallots and garlic for 7-10 minutes or until soft and starting to colour. Set aside to cool to room temperature.
2. In a large mixing bowl, combine the ground turkey, egg, walnuts, breadcrumbs, Worcestershire sauce, sage, salt, pepper and the cooled shallots. Using your hands, knead the mixture until well combined. Divide into 16 equal portions, and roll each one into a ball.
Remove the stems from the mushrooms and discard. Arrange the caps on a platter, and season the insides with a little salt and pepper. Place a ball of the turkey mixture onto each mushroom cap, and gently pat down to fill the cap.
3. Preheat one side of a lightly-oiled grate over high heat (or, if using charcoal, pile the coals to one side).
4. As soon as the grill is hot, arrange the mushrooms on the cool side of the grill. Cover and cook over indirect heat with the cover closed for 10 minutes. Top each mushroom with a pinch of cheese, then close up again and continue cooking for 5-10 minutes, or until the stuffing registers an internal temperature of 165F and the cheese is bubbly and browned. Serve immediately.