Juicy grilled hoisin burgers are piled high with lettuce and cucumber, then finished with a drizzle of creamy, addictive Yum Yum Japanese steak sauce. It adds a flavorful twist that beats ordinary mayo every time.
For a gas grill, turn all burners to high, cover, and heat grill until hot, about 10 minutes. Leave all burners on high.
To a large bowl, combine venison, green onions, 4 Tablespoons hoisin sauce, sesame oil, salt, and pepper. Stir until well combined. Divide into 4 equal portions and form into patties about 3 inches in diameter and ½-inch thick.
Lightly brush the grill grates with vegetable oil, then grill burger patties without moving them, until browned and meat easily releases from grill, about 4 to 5 minutes. Reduce grill heat to medium low, then flip burgers and continue to grill for about 2 minutes more. During the last minute of grilling, brush the patties with remaining hoisin sauce. Continue to grill until meat registers 135 degrees F for medium-rare using an instant-read meat thermometer. Transfer to a plate and let rest for 5 minutes.
Meanwhile, grill buns cut side down until slightly toasted and warm. Remove from the grill.
Build burgers by spreading Yum Yum Sauce on cut sides of buns. Add sliced cucumber to the base of the bun, then burger patty. Add lettuce to the top of burgers and close with the other bun. Serve.