Basically a meatball recipe re-purposed as burgers...
1lb Ground Beef
1/2lb Ground Pork
1/4 cup chicken stock
1 onion, chopped
1-2 garlic cloves, crushed
1/2 cup bread crumbs
1-2 eggs
1/4 cup chopped parsley
1/4 cup of Parmesan
salt and chili flakes to taste
Combine the stock, onion, and garlic in a food processor and chop until very fine. Combine with remaining ingredients and form into patties.
Did these last week over mostly indirect heat. Perhaps not everyone's idea of a perfect burger but quite tasty with bacon and all the fixins.