BURGERS: COMBINE ingredients in bowl. Shape into 1/3-lb. patties.
MAPLE Sauce: Combine ingredients in saucepan. Cook on medium heat until syrupy. Cool.
FOR each burger: Grill 1 patty to desired doneness. Top with 2 tsp. cheese and 1 tsp. lemon zest.
TOSS 1 scallion with 1 tsp. oil. Grill until lightly charred; cut in half. Lightly grill 2 Canadian bacon slices and 1 tomato slice; brush each slice with 1 tsp. Maple Sauce.
SPREAD 2 Tbsp. mayo on top half of 1 roll. Place 2 Tbsp. arugula, 2 scallion halves and 1 tomato slice on bottom half of roll. Top with prepared burger and 2 Canadian bacon slices. Cover with top of roll.