Umami-Bomb Burgers

Combine the olive oil, fish sauce, pepper, salt, grated garlic, and minced tenderloin; divide into 4 3/4-inch-thick patties. Preheat a grill pan over high heat. Brush the mold with cooking spray. Add the meatballs and onion slices to the pan; cook for 3 minutes on each side, or until just cooked through. Spread 1 teaspoon of canola mayonnaise on top and bottom of hamburger buns. On the bottom half of each bun, put 1 pie, 1 lettuce leaf, 2 thin slices of tomato, a fourth of the onion and the top half of the bun.