Preheat oven broiler.
Heat a skillet over medium-low heat, add oil, and then place patties in one layer.
Cook until heated through, firm and browned on both sides, about 4 to 6 minutes on each side.
Add 1/2 tablespoon of butter to each brioche bun and toast, then top with 1 tablespoon of mayonnaise, veggie patty, and top with cabbage slaw and cucumber before serving.
