Asian seasonings make Linda Lum’s hamburgers aromatic and tangy. You can now find Chinese five spice blends in the spice section of most supermarkets, where you’ll also find prepared plum sauce and Asian sesame oil. If you can’t find five spice, substitute this mixture: 1/8 teaspoon each ground cinnamon, ground cloves, ground ginger, and anise seeds.
Pour oil into an 8- to 10-inch nonstick frying pan over high heat; when hot, add mushrooms and stir until lightly browned, about 4 minutes. Stir in the green onions and plum sauce and remove from heat.
In a bowl, gently mix ground beef with soy sauce, sesame oil, garlic, Chinese five spice, and ginger. Shape beef mixture into four equal patties, each about 1/2 inch thick.
Lay patties on a lightly oiled barbecue grill over a solid bed of medium-hot coals or medium-high heat on a gas grill (you can hold your hand at grill level only 3 to 4 seconds); close lid on gas grill. Cook patties until no longer pink in the center (cut to test) or a thermometer inserted in center reaches 160°, 6 to 8 minutes total, turning once to brown evenly. After 5 minutes, lay bun halves, cut side down, on grill and toast lightly, 1 to 2 minutes.
Lay a lettuce leaf on each toasted bun base, top with a beef patty, and spoon mushroom mixture equally over burgers. Add salt to taste and cover with bun tops.
* Percent Daily Values are based on a 2,000 calorie diet. Your daily value may be higher or lower depending on your calorie needs.