In a cast iron skillet over high heat, add the olive oil. When the oil is shimmering, add the diced venison and stir until all the meat is browned.
Add onion, Worcestershire sauce, soy sauce, stock, brown sugar, salt, and pepper to the meat. Stir mixture until incorporated and bring to a boil. Reduce heat to a medium-low and allow to cook until all the liquid has evaporated.
Using a slotted spoon, place a mound of meat on top of the bottom hamburger bun. Add sliced dill pickles and mustard. Place the top of the bun on the burger. Get out your napkins and dig in!