In a medium bowl combine ground meats, 1 Tbsp Hoisin sauce, soy sauce, garlic, chopped onions and sweetener.
Mix with large spoon until combined.
Form into 4 large patties.
Cut up fresh pineapple into thick rings.
Heat BBQ to medium heat.
Add patties to BBQ and grill for 12-15 minutes until cooked thoroughly.
Remove from BBQ.
Place onion rings on grill and cook for 5-8 minutes, flipping so that both sides are nicely brown.
Remove from BBQ.
Place pineapple rings on BBQ and watching carefully(high sugar content of pineapple can cause it to burn quickly) grill for 5-6 minutes.
Making sure to flip and grill both sides.
Remove from BBQ.
To plate burgers, place are lettuce leaf on plate.
Place grilled patty on lettuce and also top with 1/2-1 Tbsp hoisin sauce.
Top burger with grilled onion and then grilled pineapple ring.
Wrap up burger in lettuce leaf and enjoy!