Chop cucumber and olives; combine in small bowl with vinegar and oregano. Set aside.
Place medium nonstick skillet lightly coated with cooking spray over medium-high
heat. Cook veggie burger patty for 3 to 4 minutes per side, until heated through and
lightly browned.
While the veggie burger cooks, toast bread; spread with mustard.
Place veggie burger on toast; top with cucumber mixture. Serve immediately.
The Nutrition Facts box below provides estimated nutritional information for this recipe.