In a food processor, add the mushrooms, shallots, parsley and pulse until chopped.

Transfer the mixture to a large bowl. Add the turkey, olive oil and Worcestershire sauce, 1 tsp. salt and pepper to taste.

Mix with hands until combined. Divide into 6 balls. Lightly press into 4"wide X 1" thick patties. Put on a large plate, cover and refrigerate until firm. About 30 min.

Remove the patties 30 min prior to cooking. Preheat the grill to 350 F. Brush the grates with olive oil. Grill the patties undisturbed until the bottom are grill marked. About 4-5 min. Turn 1/4 turn, cook another 4-5 min. Flip the patties and cook through. About 6-7 min more. Top each with 1-2 slices of cheese during the last 3 min of cooking.

Toast the sandwich thins, or, grill the buns until toasted. Spread condiments. Serve the patties and top with avocado or other toppings of choice.