In a medium bowl, gently mix together the venison meat, the melted lard or bacon fat, Worcestershire (or other acid) 2 tsp. of the salt, ½ tsp. of the black pepper, the seasoned salt, onion powder, and garlic powder. Do not over mix.
Use a 4oz. scoop to portion out the meat to create equally sized balls to form patties.
To form the patties: hold the portioned venison in your right hand and press down firmly with your left hand. Begin rotating the patty with your bottom hand and continue pressing down with your left. When the patty is 3.5 – 4 inches in diameter press a divot into the center that is roughly the size of a quarter (this helps prevent the burger from puffing up while cooking).
Place patties on a baking tray lined with wax or parchment paper and continue portioning and forming patties until all 8 are made. Sprinkle patties on both sides with remaining salt and pepper.
From here patties can either be made right away, wrapped in plastic and refrigerated for up to one day, or frozen. To freeze burgers: place each patty between small squares of wax paper, wrap in tinfoil, and place in a freezer-safe plastic bag. (If freezing burger patties be sure to remove from freezer and thaw in refrigerator the evening before use.)
To cook venison burgers in a cast iron pan: place pan over medium-high heat. Add 1 tablespoon of lard or bacon fat to the pan and allow to melt and coat the entire bottom. Place 2 – 3 burgers, divot side down, in preheated pan, spacing apart evenly. Cook on the first side for 3 – 4 minutes before flipping and cooking for another 2 – 3 minutes (longer for more well done). Remove from pan and add another tablespoon of bacon grease before cooking each batch of burgers. Remove from pan and immediately top with sliced cheese, if using.
To grill venison burgers: Preheat grill over medium-high heat, scraping grates with a wire brush to clean off any residue, if necessary. Add burger patties, divot side down, to grill and cook for 3 – 4 minutes, rotating patties 90 degrees once during this duration to prevent sticking. Flip and cook for another 2 – 3 minutes (longer for well done). Remove from grill and immediately top with sliced cheese, if using.
To assemble burgers: Place romaine leaf on bottom bun and top with burger patty. Add tomato and onion, if using. Spread mayo and mustard on the top bun and finish assembling the burger. Serving with a side of potato chips, fries, or a pickle!